diff --git a/pkgs/applications/graphics/ImageMagick/7.0.nix b/pkgs/applications/graphics/ImageMagick/7.0.nix
index 3b215ea24fc7..76490682477a 100644
--- a/pkgs/applications/graphics/ImageMagick/7.0.nix
+++ b/pkgs/applications/graphics/ImageMagick/7.0.nix
@@ -1,4 +1,4 @@
-{ lib, stdenv, fetchFromGitHub, pkg-config, libtool
+{ lib, stdenv, fetchFromGitHub, fetchpatch, pkg-config, libtool
 , bzip2, zlib, libX11, libXext, libXt, fontconfig, freetype, ghostscript, libjpeg, djvulibre
 , lcms2, openexr, libjxl, libpng, liblqr1, libraw, librsvg, libtiff, libxml2, openjpeg, libwebp, libheif
 , ApplicationServices
@@ -27,6 +27,14 @@ stdenv.mkDerivation rec {
     sha256 = "0r8zmk2cfmf09l94hqzfz4aspnzn178ggdbgm7w4hr0p864cbvc3";
   };
 
+  patches = [
+    # fix a type confusion bug introduced in 7.1.0-20 with commit 075565e93c71bcaaabf0ce70b7d1060bccdf0020
+    (fetchpatch {
+      url = "https://github.com/ImageMagick/ImageMagick/commit/62845d5672eca4446b952dd0ab2e3e0dab0309d4.patch";
+      sha256 = "1kni5i8b5hl69niypidm90mhir8cafi6r9i857fxdlv045h3dg4p";
+    })
+  ];
+
   outputs = [ "out" "dev" "doc" ]; # bin/ isn't really big
   outputMan = "out"; # it's tiny