diff --git a/src/V3LinkDot.cpp b/src/V3LinkDot.cpp
index 539a83d74..55f591aa8 100644
--- a/src/V3LinkDot.cpp
+++ b/src/V3LinkDot.cpp
@@ -3330,7 +3330,7 @@ class LinkDotResolveVisitor final : public VNVisitor {
             }
         }
         if (nodep->isExternProto()) {
-            if (!m_curSymp->findIdFallback(nodep->name()) && !nodep->isExternExplicit()) {
+            if (!m_curSymp->findIdFallback(nodep->name()) && nodep->isExternExplicit()) {
                 nodep->v3error("Definition not found for extern " + nodep->prettyNameQ());
             }
         }
diff --git a/test_regress/t/t_constraint_extern.v b/test_regress/t/t_constraint_extern.v
index 8a7f4602c..ec3888f08 100644
--- a/test_regress/t/t_constraint_extern.v
+++ b/test_regress/t/t_constraint_extern.v
@@ -11,7 +11,7 @@ class Packet;
    extern function void f();
    constraint cone;
    extern constraint ctwo;
-   extern constraint cmissing;  // Ok per IEEE 1800-2023 18.5.1
+   constraint cmissing;  // Ok per IEEE 1800-2023 18.5.1
 
 endclass
 
diff --git a/test_regress/t/t_constraint_extern_bad.out b/test_regress/t/t_constraint_extern_bad.out
index da6dfe795..e63efbb03 100644
--- a/test_regress/t/t_constraint_extern_bad.out
+++ b/test_regress/t/t_constraint_extern_bad.out
@@ -1,6 +1,6 @@
-%Error: t/t_constraint_extern_bad.v:8:15: Definition not found for extern 'missing_bad'
-    8 |    constraint missing_bad;
-      |               ^~~~~~~~~~~
+%Error: t/t_constraint_extern_bad.v:8:22: Definition not found for extern 'missing_bad'
+    8 |    extern constraint missing_bad;
+      |                      ^~~~~~~~~~~
 %Error: t/t_constraint_extern_bad.v:11:20: extern not found that declares 'missing_extern'
    11 | constraint Packet::missing_extern { }
       |                    ^~~~~~~~~~~~~~
diff --git a/test_regress/t/t_constraint_extern_bad.v b/test_regress/t/t_constraint_extern_bad.v
index ebeab9acf..743d9f4b1 100644
--- a/test_regress/t/t_constraint_extern_bad.v
+++ b/test_regress/t/t_constraint_extern_bad.v
@@ -5,7 +5,7 @@
 // SPDX-License-Identifier: CC0-1.0
 
 class Packet;
-   constraint missing_bad;
+   extern constraint missing_bad;
 endclass
 
 constraint Packet::missing_extern { }