diff --git a/src/plugins/yamlcpp/testmod_yamlcpp.c b/src/plugins/yamlcpp/testmod_yamlcpp.c
index dbc35c558a2..c1ca544983d 100644
--- a/src/plugins/yamlcpp/testmod_yamlcpp.c
+++ b/src/plugins/yamlcpp/testmod_yamlcpp.c
@@ -33,6 +33,9 @@
 	ksDel (keySet);                                                                                                                    \
 	PLUGIN_CLOSE ()
 
+/* We use this prefix in all header files that contain test data. */
+#define PREFIX "user/examples/yamlcpp/"
+
 // -- Functions ----------------------------------------------------------------------------------------------------------------------------
 
 static void test_contract (void)
diff --git a/src/plugins/yamlcpp/yamlcpp/flat_block_mapping.h b/src/plugins/yamlcpp/yamlcpp/flat_block_mapping.h
index eb85bc9dd37..8687b2f966a 100644
--- a/src/plugins/yamlcpp/yamlcpp/flat_block_mapping.h
+++ b/src/plugins/yamlcpp/yamlcpp/flat_block_mapping.h
@@ -1,7 +1,5 @@
 // clang-format off
 
-#define PREFIX "user/examples/yamlcpp/"
-
 ksNew (10,
        keyNew (PREFIX "longish key", KEY_VALUE, "10-9-8-7 everybody’s coming to burn this city", KEY_END),
        keyNew (PREFIX "double quoted", KEY_VALUE, "single quoted", KEY_END),
diff --git a/src/plugins/yamlcpp/yamlcpp/flat_flow_mapping.h b/src/plugins/yamlcpp/yamlcpp/flat_flow_mapping.h
index 122babf1ade..ad80ec0aecc 100644
--- a/src/plugins/yamlcpp/yamlcpp/flat_flow_mapping.h
+++ b/src/plugins/yamlcpp/yamlcpp/flat_flow_mapping.h
@@ -1,7 +1,5 @@
 // clang-format off
 
-#define PREFIX "user/examples/yamlcpp/"
-
 ksNew (10,
        keyNew (PREFIX "space invader", KEY_VALUE, "👾", KEY_END),
        keyNew (PREFIX "text", KEY_VALUE, "1337", KEY_END),
diff --git a/src/plugins/yamlcpp/yamlcpp/nested_block_mapping.h b/src/plugins/yamlcpp/yamlcpp/nested_block_mapping.h
index 9d3f3f56af5..9308a2efc25 100644
--- a/src/plugins/yamlcpp/yamlcpp/nested_block_mapping.h
+++ b/src/plugins/yamlcpp/yamlcpp/nested_block_mapping.h
@@ -1,7 +1,5 @@
 // clang-format off
 
-#define PREFIX "user/examples/yamlcpp/"
-
 ksNew (10,
        keyNew (PREFIX "bloc/party/little", KEY_VALUE, "thoughts", KEY_END),
        keyNew (PREFIX "bloc/party/silent", KEY_VALUE, "alarm", KEY_END),
diff --git a/src/plugins/yamlcpp/yamlcpp/nested_mixed_mapping.h b/src/plugins/yamlcpp/yamlcpp/nested_mixed_mapping.h
index b135c1357ac..26087d4b956 100644
--- a/src/plugins/yamlcpp/yamlcpp/nested_mixed_mapping.h
+++ b/src/plugins/yamlcpp/yamlcpp/nested_mixed_mapping.h
@@ -1,7 +1,5 @@
 // clang-format off
 
-#define PREFIX "user/examples/yamlcpp/"
-
 ksNew (20,
        keyNew (PREFIX "bloc/party/little", KEY_VALUE, "thoughts", KEY_END),
        keyNew (PREFIX "bloc/party/silent", KEY_VALUE, "alarm", KEY_END),
diff --git a/src/plugins/yamlcpp/yamlcpp/nested_sequences.h b/src/plugins/yamlcpp/yamlcpp/nested_sequences.h
index 0d1f5ebb3a4..30db77e5126 100644
--- a/src/plugins/yamlcpp/yamlcpp/nested_sequences.h
+++ b/src/plugins/yamlcpp/yamlcpp/nested_sequences.h
@@ -1,7 +1,5 @@
 // clang-format off
 
-#define PREFIX "user/examples/yamlcpp/"
-
 ksNew (20,
        keyNew (PREFIX "American Football", KEY_BINARY, KEY_META, "array", "#2", KEY_END),
        keyNew (PREFIX "American Football/#0", KEY_VALUE, "American Football (EP)", KEY_END),
diff --git a/src/plugins/yamlcpp/yamlcpp/simple_sequence.h b/src/plugins/yamlcpp/yamlcpp/simple_sequence.h
index 1261adce1e8..d306f05ad9e 100644
--- a/src/plugins/yamlcpp/yamlcpp/simple_sequence.h
+++ b/src/plugins/yamlcpp/yamlcpp/simple_sequence.h
@@ -1,7 +1,5 @@
 // clang-format off
 
-#define PREFIX "user/examples/yamlcpp/"
-
 ksNew (20,
        keyNew (PREFIX "#0", KEY_VALUE, "You,", KEY_END),
        keyNew (PREFIX "#1", KEY_VALUE, "Me, &", KEY_END),