diff --git a/gst/inter/gstinteraudiosrc.c b/gst/inter/gstinteraudiosrc.c
index 456d90772d..b3417a7378 100644
--- a/gst/inter/gstinteraudiosrc.c
+++ b/gst/inter/gstinteraudiosrc.c
@@ -433,6 +433,7 @@ gst_inter_audio_src_fixate (GstBaseSrc * src, GstCaps * caps)
   GST_DEBUG_OBJECT (src, "fixate");
 
   caps = gst_caps_make_writable (caps);
+  caps = gst_caps_truncate (caps);
 
   structure = gst_caps_get_structure (caps, 0);
 
diff --git a/gst/inter/gstintervideosrc.c b/gst/inter/gstintervideosrc.c
index 4abde92187..d424d03449 100644
--- a/gst/inter/gstintervideosrc.c
+++ b/gst/inter/gstintervideosrc.c
@@ -371,7 +371,7 @@ gst_inter_video_src_fixate (GstBaseSrc * src, GstCaps * caps)
   GST_DEBUG_OBJECT (src, "fixate");
 
   caps = gst_caps_make_writable (caps);
-
+  caps = gst_caps_truncate (caps);
   structure = gst_caps_get_structure (caps, 0);
 
   gst_structure_fixate_field_string (structure, "format", "I420");