diff --git a/api-testcases/test-del-prop.c b/api-testcases/test-del-prop.c
index 0f5f3607..5bcabd2a 100644
--- a/api-testcases/test-del-prop.c
+++ b/api-testcases/test-del-prop.c
@@ -13,15 +13,15 @@ final array: ["foo","bar",null]
 final top: 3
 ==> rc=0, result='undefined'
 *** test_1b (duk_pcall)
-==> rc=1, result='TypeError: property not configurable'
+==> rc=1, result='TypeError: not configurable'
 *** test_1c (duk_pcall)
-==> rc=1, result='TypeError: property not configurable'
+==> rc=1, result='TypeError: not configurable'
 *** test_1d (duk_safe_call)
 ==> rc=1, result='Error: invalid index'
 *** test_1e (duk_safe_call)
 ==> rc=1, result='Error: invalid index'
 *** test_1f (duk_safe_call)
-==> rc=1, result='TypeError: invalid base reference for property delete'
+==> rc=1, result='TypeError: invalid base value'
 *** test_2a (duk_safe_call)
 delete obj.foo -> rc=1
 delete obj.nonexistent -> rc=1
@@ -36,9 +36,9 @@ final array: ["foo","bar",null]
 final top: 3
 ==> rc=0, result='undefined'
 *** test_2b (duk_pcall)
-==> rc=1, result='TypeError: property not configurable'
+==> rc=1, result='TypeError: not configurable'
 *** test_2c (duk_pcall)
-==> rc=1, result='TypeError: property not configurable'
+==> rc=1, result='TypeError: not configurable'
 *** test_2d (duk_safe_call)
 ==> rc=1, result='Error: invalid index'
 *** test_2e (duk_safe_call)
@@ -54,7 +54,7 @@ final array: ["foo","bar",null]
 final top: 3
 ==> rc=0, result='undefined'
 *** test_3b (duk_pcall)
-==> rc=1, result='TypeError: property not configurable'
+==> rc=1, result='TypeError: not configurable'
 *** test_3c (duk_safe_call)
 ==> rc=1, result='Error: invalid index'
 *** test_3d (duk_safe_call)
diff --git a/api-testcases/test-get-prop.c b/api-testcases/test-get-prop.c
index 6051c4ef..4042f42c 100644
--- a/api-testcases/test-get-prop.c
+++ b/api-testcases/test-get-prop.c
@@ -20,7 +20,7 @@ configuration setting present, value: setting value
 final top: 4
 ==> rc=0, result='undefined'
 *** test_1e (duk_safe_call)
-==> rc=1, result='TypeError: invalid base reference for property read'
+==> rc=1, result='TypeError: invalid base value'
 *** test_2a (duk_safe_call)
 obj.foo -> rc=1, result='fooval'
 obj.nonexistent -> rc=0, result='undefined'
diff --git a/api-testcases/test-has-prop.c b/api-testcases/test-has-prop.c
index 531250e6..b6ecad39 100644
--- a/api-testcases/test-has-prop.c
+++ b/api-testcases/test-has-prop.c
@@ -13,9 +13,9 @@ final top: 3
 *** test_1c (duk_safe_call)
 ==> rc=1, result='Error: invalid index'
 *** test_1d (duk_safe_call)
-==> rc=1, result='TypeError: invalid base reference for property existence check'
+==> rc=1, result='TypeError: invalid base value'
 *** test_1e (duk_safe_call)
-==> rc=1, result='TypeError: invalid base reference for property existence check'
+==> rc=1, result='TypeError: invalid base value'
 *** test_2a (duk_safe_call)
 obj.foo -> rc=1
 obj.nonexistent -> rc=0
diff --git a/api-testcases/test-pcall-prop.c b/api-testcases/test-pcall-prop.c
index 5f3d582d..15766318 100644
--- a/api-testcases/test-pcall-prop.c
+++ b/api-testcases/test-pcall-prop.c
@@ -15,7 +15,7 @@ rc=0, result='21'
 rc=1, result='Error: my error'
 ==> rc=0, result='undefined'
 *** test_5 (duk_safe_call)
-rc=1, result='TypeError: invalid base reference for property read'
+rc=1, result='TypeError: invalid base value'
 ==> rc=0, result='undefined'
 *** test_6 (duk_safe_call)
 rc=1, result='RangeError: getter error'
@@ -24,7 +24,7 @@ rc=1, result='RangeError: getter error'
 rc=1, result='Error: invalid index'
 ==> rc=0, result='undefined'
 *** test_8 (duk_safe_call)
-rc=1, result='TypeError: call target not callable'
+rc=1, result='TypeError: not callable'
 ==> rc=0, result='undefined'
 *** test_9 (duk_safe_call)
 ==> rc=1, result='Error: invalid call args'
diff --git a/api-testcases/test-put-prop-primbase.c b/api-testcases/test-put-prop-primbase.c
index 11b7efb0..f048f663 100644
--- a/api-testcases/test-put-prop-primbase.c
+++ b/api-testcases/test-put-prop-primbase.c
@@ -4,7 +4,7 @@ put rc=0
 final top: 1
 ==> rc=0, result='undefined'
 *** test_put (duk_pcall)
-==> rc=1, result='TypeError: non-object base reference'
+==> rc=1, result='TypeError: invalid base value'
 ===*/
 
 int test_put(duk_context *ctx) {
diff --git a/api-testcases/test-put-prop.c b/api-testcases/test-put-prop.c
index e4f76d43..30b669c1 100644
--- a/api-testcases/test-put-prop.c
+++ b/api-testcases/test-put-prop.c
@@ -23,7 +23,7 @@ final top: 2
 strict: 1
 get Math -> rc=1
 Math.PI=3.141592653589793
-==> rc=1, result='TypeError: property not writable'
+==> rc=1, result='TypeError: not writable'
 *** test_ex_accessor_wo_setter (duk_safe_call)
 strict: 0
 eval:
@@ -56,7 +56,7 @@ eval:
     return o;
 })()
 top after eval: 1
-==> rc=1, result='TypeError: undefined setter for accessor'
+==> rc=1, result='TypeError: setter undefined'
 *** test_ex_setter_throws (duk_safe_call)
 strict: 0
 eval:
@@ -115,7 +115,7 @@ strict: 1
 eval:
 (function () { var o = { foo: 1 }; Object.preventExtensions(o); return o; })()
 top after eval: 1
-==> rc=1, result='TypeError: object not extensible'
+==> rc=1, result='TypeError: not extensible'
 ===*/
 
 /* Test property writing API call.