diff --git a/src/estimates/simp.py b/src/estimates/simp.py
index b2e0186..6b1b7c8 100644
--- a/src/estimates/simp.py
+++ b/src/estimates/simp.py
@@ -220,7 +220,7 @@ def activate(self, state: ProofState) -> list[ProofState]:
             newvar = new_var("pos_real", name)
         else:
             raise ValueError(
-                f"INCONSISTENCY: {name}:{typeof} was somehow proven positive, which is impossible."
+                f"INCONSISTENCY: {name}:{typeof(var)} was somehow proven positive, which is impossible."
             )
 
         print(f"{name} is now of type {typeof(newvar)}.")
@@ -277,7 +277,7 @@ def activate(self, state: ProofState) -> list[ProofState]:
             newvar = new_var("nonneg_real", name)
         else:
             raise ValueError(
-                f"INCONSISTENCY: {name}:{typeof} was somehow proven nonnegative, which is impossible."
+                f"INCONSISTENCY: {name}:{typeof(var)} was somehow proven nonnegative, which is impossible."
             )
 
         print(f"{name} is now of type {typeof(newvar)}.")
@@ -334,7 +334,7 @@ def activate(self, state: ProofState) -> list[ProofState]:
             newvar = new_var("nonzero_real", name)
         else:
             raise ValueError(
-                f"INCONSISTENCY: {name}:{typeof} was somehow proven positive, which is impossible."
+                f"INCONSISTENCY: {name}:{typeof(var)} was somehow proven nonzero, which is impossible."
             )
 
         print(f"{name} is now of type {typeof(newvar)}.")
diff --git a/tests/test_all.py b/tests/test_all.py
index 862b3ed..a453b2d 100644
--- a/tests/test_all.py
+++ b/tests/test_all.py
@@ -110,3 +110,14 @@ def test_subst_all_solution_reversed(self, capsys):
     def test_sympy_simplify_solution(self, capsys):
         sympy_simplify_solution()
         self.proof_complete(capsys)
+
+    def test_type_tactic_inconsistency_messages(self):
+        """Inconsistency errors should call typeof(var), and IsNonzero should say nonzero."""
+        import inspect
+        from estimates.simp import IsNonzero, IsPositive, IsNonnegative
+        src = inspect.getsource(IsNonzero.activate)
+        assert "typeof(var)" in src
+        assert "proven nonzero" in src
+        assert "proven positive" not in src
+        assert "typeof(var)" in inspect.getsource(IsPositive.activate)
+        assert "typeof(var)" in inspect.getsource(IsNonnegative.activate)