diff --git a/INSTALL.md b/INSTALL.md
index 4c2114db85..40270955af 100644
--- a/INSTALL.md
+++ b/INSTALL.md
@@ -56,8 +56,7 @@ NEW or CHANGED MINIMUM dependencies since the last major release are **bold**.
    or for capturing images from a camera:
      * **OpenCV 4.x** (tested through 4.10)
  * If you want support for GIF images:
-     * giflib >= 4.1 (tested through 5.2; 5.0+ is strongly recommended for
-       stability and thread safety)
+     * **giflib >= 5.0** (tested through 5.2)
  * If you want support for HEIF/HEIC or AVIF images:
      * libheif >= 1.3 (1.7 required for AVIF support, 1.16 required for
        correct orientation support, tested through 1.17.6)
diff --git a/src/cmake/externalpackages.cmake b/src/cmake/externalpackages.cmake
index dbfd17e898..71439639c1 100644
--- a/src/cmake/externalpackages.cmake
+++ b/src/cmake/externalpackages.cmake
@@ -162,10 +162,8 @@ checked_find_package (TBB 2017
 checked_find_package (DCMTK CONFIG VERSION_MIN 3.6.1)
 
 checked_find_package (FFmpeg VERSION_MIN 4.0)
-checked_find_package (GIF
-                      VERSION_MIN 4
-                      RECOMMEND_MIN 5.0
-                      RECOMMEND_MIN_REASON "for stability and thread safety")
+
+checked_find_package (GIF VERSION_MIN 5.0)
 
 # For HEIF/HEIC/AVIF formats
 checked_find_package (Libheif VERSION_MIN 1.3
diff --git a/src/gif.imageio/gifinput.cpp b/src/gif.imageio/gifinput.cpp
index e95f7096d9..45cd33cc9e 100644
--- a/src/gif.imageio/gifinput.cpp
+++ b/src/gif.imageio/gifinput.cpp
@@ -19,7 +19,7 @@
 
 // for older giflib versions
 #ifndef GIFLIB_MAJOR
-#    define GIFLIB_MAJOR 4
+#    error "GIFLIB 5.0 minimum required"
 #endif
 
 #ifndef DISPOSAL_UNSPECIFIED
@@ -132,12 +132,8 @@ OIIO_EXPORT const char* gif_input_extensions[] = { "gif", NULL };
 OIIO_EXPORT const char*
 gif_imageio_library_version()
 {
-#if defined(GIFLIB_MAJOR) && defined(GIFLIB_MINOR) && defined(GIFLIB_RELEASE)
     return "gif_lib " OIIO_STRINGIZE(GIFLIB_MAJOR) "." OIIO_STRINGIZE(
         GIFLIB_MINOR) "." OIIO_STRINGIZE(GIFLIB_RELEASE);
-#else
-    return "gif_lib unknown version";
-#endif
 }
 
 OIIO_PLUGIN_EXPORTS_END
@@ -408,20 +404,12 @@ GIFInput::seek_subimage(int subimage, int miplevel)
     if (!m_gif_file) {
         if (!ioproxy_use_or_open(m_filename))
             return false;
-#if GIFLIB_MAJOR >= 5
         int giflib_error;
         m_gif_file = DGifOpen(this, readFunc, &giflib_error);
         if (!m_gif_file) {
             errorfmt("{}", GifErrorString(giflib_error));
             return false;
         }
-#else
-        m_gif_file = DGifOpen(this, readFunc);
-        if (!m_gif_file) {
-            errorfmt("Error opening GIF");
-            return false;
-        }
-#endif
         m_subimage = -1;
         m_canvas.resize(m_gif_file->SWidth * m_gif_file->SHeight * 4);
     }
@@ -459,27 +447,12 @@ GIFInput::seek_subimage(int subimage, int miplevel)
 
 
 
-static spin_mutex gif_error_mutex;
-
-
 void
 GIFInput::report_last_error(void)
 {
-    // N.B. Only GIFLIB_MAJOR >= 5 looks properly thread-safe, in that the
-    // error is guaranteed to be specific to this open file.  We use a  spin
-    // mutex to prevent a thread clash for older versions, but it still
-    // appears to be a global call, so we can't be absolutely sure that the
-    // error was for *this* file.  So if you're using giflib prior to
-    // version 5, beware.
-#if GIFLIB_MAJOR >= 5
+    // GIFLIB_MAJOR >= 5 looks properly thread-safe, in that the error is
+    // guaranteed to be specific to this open file.
     errorfmt("{}", GifErrorString(m_gif_file->Error));
-#elif GIFLIB_MAJOR == 4 && GIFLIB_MINOR >= 2
-    spin_lock lock(gif_error_mutex);
-    errorfmt("{}", GifErrorString());
-#else
-    spin_lock lock(gif_error_mutex);
-    errorfmt("GIF error {}", GifLastError());
-#endif
 }