diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index 04db557a..aaff060e 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -94,10 +94,7 @@ jobs:
   #     comes with Ubuntu is 0.75 which has a couple of bugs triggered
   #     by our codebase (they've been resolved on trunk though so we
   #     may want to change this soon).
-  # [2] We supply --allow-untyped-calls because even though drgn has
-  #     stubs on typeshed now, there are still some untyped functions
-  #     (mainly in the helper API).
-  # [3] We supply --ignore-missing-imports to the tests package because
+  # [2] We supply --ignore-missing-imports to the tests package because
   #     pytest doesn't provide stubs on typeshed.
   #
   mypy:
@@ -109,7 +106,7 @@ jobs:
           python-version: '3.6'
       - run: ./.github/scripts/install-drgn.sh
       - run: python3 -m pip install mypy==0.730
-      - run: python3 -m mypy --strict --allow-untyped-calls --show-error-codes -p sdb
+      - run: python3 -m mypy --strict --show-error-codes -p sdb
       - run: python3 -m mypy --strict --ignore-missing-imports --show-error-codes -p tests
   #
   # Verify that "shfmt" ran successfully against our shell scripts.
diff --git a/sdb/command.py b/sdb/command.py
index bc75b046..670b6037 100644
--- a/sdb/command.py
+++ b/sdb/command.py
@@ -643,13 +643,13 @@ def _call(self, objs: Iterable[drgn.Object]) -> Iterable[drgn.Object]:
         the types as we go.
         """
         assert self.input_type is not None
-        type_ = target.get_type(self.input_type)
+        expected_type = type_canonicalize_name(self.input_type)
         for obj in objs:
-            if obj.type_ != type_:
+            if type_canonical_name(obj.type_) != expected_type:
                 raise CommandError(
                     self.name,
                     'expected input of type {}, but received {}'.format(
-                        type_, obj.type_))
+                        expected_type, type_canonical_name(obj.type_)))
 
             yield from self.walk(obj)
 
diff --git a/sdb/commands/internal/util.py b/sdb/commands/internal/util.py
index 765832f5..7eb7a046 100644
--- a/sdb/commands/internal/util.py
+++ b/sdb/commands/internal/util.py
@@ -24,13 +24,46 @@ def get_valid_type_by_name(cmd: sdb.Command, tname: str) -> drgn.Type:
     """
     Given a type name in string form (`tname`) without any C keyword
     prefixes (e.g. 'struct', 'enum', 'class', 'union'), return the
-    corresponding drgn.Type object.
+    corresponding drgn.Type object. If `tname` starts with a C keyword
+    we just return the type as is.
 
     This function is used primarily by commands that accept a type
     name as an argument and exist only to save keystrokes for the
     user.
     """
-    if tname in ['struct', 'enum', 'union', 'class']:
+    TYPE_KEYWORDS = ['struct', 'enum', 'union', 'class']
+
+    tokens = tname.split()
+    if len(tokens) > 2:
+        #
+        # drgn fails in all kinds of ways when we pass it an
+        # invalid type that consists of more than 2 text tokens.
+        #
+        raise sdb.CommandError(cmd.name,
+                               f"input '{tname}' is not a valid type name")
+
+    if len(tokens) == 2:
+        if tokens[0] not in TYPE_KEYWORDS or tokens[1] in TYPE_KEYWORDS:
+            #
+            # For the same reason mentioned in the above comment
+            # we also ensure that someone may not invalid two-token
+            # input that has the following errors:
+            # 1] Doesn't start with a type keyword - e.g "bogus type"
+            # 2] Has a type keyword as its type name (also see
+            #    comment below) - e.g. struct struct
+            #
+            raise sdb.CommandError(cmd.name,
+                                   f"input '{tname}' is not a valid type name")
+        try:
+            return sdb.get_type(tname)
+        except LookupError as err:
+            raise sdb.CommandError(cmd.name,
+                                   f"couldn't find type '{tname}'") from err
+        except SyntaxError as err:
+            raise sdb.CommandError(
+                cmd.name, f"input '{tname}' is not a valid type name") from err
+
+    if tname in TYPE_KEYWORDS:
         #
         # Note: We have to do this because currently in drgn
         # prog.type('struct') returns a different error than
@@ -82,9 +115,12 @@ def get_valid_type_by_name(cmd: sdb.Command, tname: str) -> drgn.Type:
         # it is a structure, an enum, or a union.
         #
         pass
-    for prefix in ["struct ", "enum ", "union "]:
+    except SyntaxError as err:
+        raise sdb.CommandError(
+            cmd.name, f"input '{tname}' is not a valid type name") from err
+    for prefix in TYPE_KEYWORDS:
         try:
-            return sdb.get_type(f"{prefix}{tname}")
+            return sdb.get_type(f"{prefix} {tname}")
         except LookupError:
             pass
     raise sdb.CommandError(
diff --git a/sdb/commands/ptype.py b/sdb/commands/ptype.py
index 76395239..2c3c0002 100644
--- a/sdb/commands/ptype.py
+++ b/sdb/commands/ptype.py
@@ -50,16 +50,15 @@ class PType(sdb.Command):
 
         Print enums and unions:
 
-            sdb> ptype zfs_case v_t thread_union
+            sdb> ptype zfs_case 'struct v' thread_union
             enum zfs_case {
                     ZFS_CASE_SENSITIVE = 0,
                     ZFS_CASE_INSENSITIVE = 1,
                     ZFS_CASE_MIXED = 2,
             }
-            typedef union {
-                    iv_t e;
-                    uint8_t b[8];
-            } v_t
+            struct v {
+                    uint8_t b[16];
+            }
             union thread_union {
                     struct task_struct task;
                     unsigned long stack[2048];
diff --git a/tests/integration/data/regression_output/core/ptype $abc b/tests/integration/data/regression_output/core/ptype $abc
new file mode 100644
index 00000000..778d3f1f
--- /dev/null
+++ b/tests/integration/data/regression_output/core/ptype $abc	
@@ -0,0 +1 @@
+sdb: ptype: input '$abc' is not a valid type name
diff --git a/tests/integration/data/regression_output/core/ptype 'a b c' b/tests/integration/data/regression_output/core/ptype 'a b c'
new file mode 100644
index 00000000..a01fdde4
--- /dev/null
+++ b/tests/integration/data/regression_output/core/ptype 'a b c'	
@@ -0,0 +1 @@
+sdb: ptype: input 'a b c' is not a valid type name
diff --git a/tests/integration/data/regression_output/core/ptype 'bogus union' b/tests/integration/data/regression_output/core/ptype 'bogus union'
new file mode 100644
index 00000000..cc1731b6
--- /dev/null
+++ b/tests/integration/data/regression_output/core/ptype 'bogus union'	
@@ -0,0 +1 @@
+sdb: ptype: input 'bogus union' is not a valid type name
diff --git a/tests/integration/data/regression_output/core/ptype 'struct bogus' b/tests/integration/data/regression_output/core/ptype 'struct bogus'
new file mode 100644
index 00000000..70772673
--- /dev/null
+++ b/tests/integration/data/regression_output/core/ptype 'struct bogus'	
@@ -0,0 +1 @@
+sdb: ptype: couldn't find type 'struct bogus'
diff --git a/tests/integration/data/regression_output/core/ptype 'struct union' b/tests/integration/data/regression_output/core/ptype 'struct union'
new file mode 100644
index 00000000..5cf94487
--- /dev/null
+++ b/tests/integration/data/regression_output/core/ptype 'struct union'	
@@ -0,0 +1 @@
+sdb: ptype: input 'struct union' is not a valid type name
diff --git a/tests/integration/data/regression_output/core/ptype 'struct' b/tests/integration/data/regression_output/core/ptype 'struct'
new file mode 100644
index 00000000..3a998af7
--- /dev/null
+++ b/tests/integration/data/regression_output/core/ptype 'struct'	
@@ -0,0 +1 @@
+sdb: ptype: skip keyword 'struct' or quote your type "struct <typename>"
diff --git a/tests/integration/data/regression_output/core/ptype 'union struct struct' b/tests/integration/data/regression_output/core/ptype 'union struct struct'
new file mode 100644
index 00000000..dd412f24
--- /dev/null
+++ b/tests/integration/data/regression_output/core/ptype 'union struct struct'	
@@ -0,0 +1 @@
+sdb: ptype: input 'union struct struct' is not a valid type name
diff --git a/tests/integration/data/regression_output/core/ptype 2abc b/tests/integration/data/regression_output/core/ptype 2abc
new file mode 100644
index 00000000..39f91fb4
--- /dev/null
+++ b/tests/integration/data/regression_output/core/ptype 2abc	
@@ -0,0 +1 @@
+sdb: ptype: input '2abc' is not a valid type name
diff --git a/tests/integration/data/regression_output/core/ptype @ b/tests/integration/data/regression_output/core/ptype @
new file mode 100644
index 00000000..ac8e79dd
--- /dev/null
+++ b/tests/integration/data/regression_output/core/ptype @	
@@ -0,0 +1 @@
+sdb: ptype: input '@' is not a valid type name
diff --git a/tests/integration/data/regression_output/core/ptype zfs_case v_t thread_union b/tests/integration/data/regression_output/core/ptype zfs_case 'struct v' thread_union
similarity index 78%
rename from tests/integration/data/regression_output/core/ptype zfs_case v_t thread_union
rename to tests/integration/data/regression_output/core/ptype zfs_case 'struct v' thread_union
index 6d123d97..10ab01f0 100644
--- a/tests/integration/data/regression_output/core/ptype zfs_case v_t thread_union	
+++ b/tests/integration/data/regression_output/core/ptype zfs_case 'struct v' thread_union	
@@ -3,10 +3,9 @@ enum zfs_case {
 	ZFS_CASE_INSENSITIVE = 1,
 	ZFS_CASE_MIXED = 2,
 }
-typedef union {
-	iv_t e;
-	uint8_t b[8];
-} v_t
+struct v {
+	uint8_t b[16];
+}
 union thread_union {
 	struct task_struct task;
 	unsigned long stack[2048];
diff --git a/tests/integration/data/regression_output/linux/echo 0x0 | cpu_counter_sum b/tests/integration/data/regression_output/linux/echo 0x0 | cpu_counter_sum
index be77fffa..c4445251 100644
--- a/tests/integration/data/regression_output/linux/echo 0x0 | cpu_counter_sum	
+++ b/tests/integration/data/regression_output/linux/echo 0x0 | cpu_counter_sum	
@@ -1 +1 @@
-sdb: cpu_counter_sum: invalid memory access: could not read memory from kdump: Cannot get page I/O address: PDPT table not present: pgd[0] = 0x0: 0x8
+sdb: cpu_counter_sum: invalid memory access: could not read memory from kdump: Cannot get page I/O address: PDPT table not present: p4d[0] = 0x0: 0x8
diff --git a/tests/integration/test_core_generic.py b/tests/integration/test_core_generic.py
index 0a0fea28..b65aabdb 100644
--- a/tests/integration/test_core_generic.py
+++ b/tests/integration/test_core_generic.py
@@ -119,7 +119,7 @@
     # ptype
     "ptype spa_t",
     "ptype spa vdev",
-    "ptype zfs_case v_t thread_union",
+    "ptype zfs_case 'struct v' thread_union",
     "ptype 'struct spa'",
 
     # sizeof
@@ -181,8 +181,18 @@
 
     # ptype - bogus type
     "ptype bogus_t",
+    "ptype 'struct bogus'",
+    "ptype 'a b c'",
     # ptype - freestanding C keyword
     "ptype struct spa",
+    "ptype 'struct'",
+    "ptype 'struct union'",
+    "ptype 'bogus union'",
+    "ptype 'union struct struct'",
+    # ptype - invalid characters
+    "ptype @",
+    "ptype 2abc",
+    "ptype $abc",
 
     # pretty printer passed incorrect type
     "spa | range_tree",