diff --git a/src/eval.c b/src/eval.c
index dcaf2f0..c81ece1 100644
--- a/src/eval.c
+++ b/src/eval.c
@@ -5560,7 +5560,7 @@
 	    break;
 	case VAR_UNKNOWN:
 	case VAR_VOID:
-	    internal_error("tv_get_number(UNKNOWN)");
+	    internal_error_no_abort("tv_get_number(UNKNOWN)");
 	    break;
     }
     if (denote == NULL)		// useful for values that must be unsigned
@@ -5614,7 +5614,7 @@
 	    break;
 	case VAR_UNKNOWN:
 	case VAR_VOID:
-	    internal_error("tv_get_float(UNKNOWN)");
+	    internal_error_no_abort("tv_get_float(UNKNOWN)");
 	    break;
     }
     return 0;
@@ -5886,7 +5886,7 @@
 	    break;
 	case VAR_UNKNOWN:
 	case VAR_VOID:
-	    internal_error("copy_tv(UNKNOWN)");
+	    internal_error_no_abort("copy_tv(UNKNOWN)");
 	    break;
     }
 }
@@ -5965,7 +5965,7 @@
 	    break;
 	case VAR_UNKNOWN:
 	case VAR_VOID:
-	    internal_error("item_copy(UNKNOWN)");
+	    internal_error_no_abort("item_copy(UNKNOWN)");
 	    ret = FAIL;
     }
     --recurse;