diff --git a/modules/juce_graphics/image_formats/jpglib/jdmaster.c b/modules/juce_graphics/image_formats/jpglib/jdmaster.c
index 8c7ec43da12b..c82368f78dd1 100644
--- a/modules/juce_graphics/image_formats/jpglib/jdmaster.c
+++ b/modules/juce_graphics/image_formats/jpglib/jdmaster.c
@@ -319,7 +319,8 @@ master_selection (j_decompress_ptr cinfo)
     if (cinfo->raw_data_out)
       ERREXIT(cinfo, JERR_NOTIMPL);
     /* 2-pass quantizer only works in 3-component color space. */
-    if (cinfo->out_color_components != 3) {
+    if (cinfo->out_color_components != 3 ||
+        cinfo->out_color_space == JCS_RGB565) {
       cinfo->enable_1pass_quant = TRUE;
       cinfo->enable_external_quant = FALSE;
       cinfo->enable_2pass_quant = FALSE;
diff --git a/modules/juce_graphics/image_formats/jpglib/jquant2.c b/modules/juce_graphics/image_formats/jpglib/jquant2.c
index 8f50d536ab9f..50d829cc6eae 100644
--- a/modules/juce_graphics/image_formats/jpglib/jquant2.c
+++ b/modules/juce_graphics/image_formats/jpglib/jquant2.c
@@ -1256,7 +1256,8 @@ jinit_2pass_quantizer (j_decompress_ptr cinfo)
   cquantize->error_limiter = NULL;
 
   /* Make sure jdmaster didn't give me a case I can't handle */
-  if (cinfo->out_color_components != 3)
+  if (cinfo->out_color_components != 3 ||
+      cinfo->out_color_space == JCS_RGB565)
     ERREXIT(cinfo, JERR_NOTIMPL);
 
   /* Allocate the histogram/inverse colormap storage */