diff --git a/gnu/local.mk b/gnu/local.mk
index 9986b01537..a1cc397f3b 100644
--- a/gnu/local.mk
+++ b/gnu/local.mk
@@ -872,7 +872,6 @@ dist_patch_DATA =						\
   %D%/packages/patches/awesome-reproducible-png.patch		\
   %D%/packages/patches/aws-c-auth-cmake-prefix.patch		\
   %D%/packages/patches/aws-c-auth-disable-networking-tests.patch\
-  %D%/packages/patches/aws-c-cal-cmake-prefix.patch		\
   %D%/packages/patches/aws-c-compression-cmake-prefix.patch	\
   %D%/packages/patches/aws-c-event-stream-cmake-prefix.patch  \
   %D%/packages/patches/aws-c-http-cmake-prefix.patch		\
diff --git a/gnu/packages/c.scm b/gnu/packages/c.scm
index 1479cf847d..a537988abe 100644
--- a/gnu/packages/c.scm
+++ b/gnu/packages/c.scm
@@ -669,7 +669,8 @@ (define-public aws-c-io
 (define-public aws-c-cal
   (package
     (name "aws-c-cal")
-    (version "0.5.11")
+    ; Update only when updating aws-crt-cpp.
+    (version "0.5.12")
     (source (origin
               (method git-fetch)
               (uri (git-reference
@@ -678,12 +679,13 @@ (define-public aws-c-cal
               (file-name (git-file-name name version))
               (sha256
                (base32
-                "0rqqk4n56h8sf4q070rhgjwas04j8h0vq4wl1alq5l1rqq72qqdf"))
-              (patches (search-patches "aws-c-cal-cmake-prefix.patch"))))
+                "09zqf610x4g2mcjcaf9nh88k6dkw14pi721yr8hxb5rmsx7rlfrb"))))
     (build-system cmake-build-system)
     (arguments
      '(#:configure-flags
-       '("-DBUILD_SHARED_LIBS=ON")))
+       (list "-DBUILD_SHARED_LIBS=ON"
+             (string-append "-DCMAKE_PREFIX_PATH="
+                            (assoc-ref %build-inputs "aws-c-common")))))
     (propagated-inputs
      `(("aws-c-common" ,aws-c-common)))
     (inputs
diff --git a/gnu/packages/patches/aws-c-cal-cmake-prefix.patch b/gnu/packages/patches/aws-c-cal-cmake-prefix.patch
deleted file mode 100644
index 1ee7aa851d..0000000000
--- a/gnu/packages/patches/aws-c-cal-cmake-prefix.patch
+++ /dev/null
@@ -1,13 +0,0 @@
---- a/CMakeLists.txt
-+++ b/CMakeLists.txt
-@@ -10,6 +10,10 @@ endif()
- 
- option(BYO_CRYPTO "Set this if you want to provide your own cryptography implementation. This will cause the defaults to not be compiled." OFF)
- 
-+if (DEFINED ENV{CMAKE_PREFIX_PATH})
-+    set(CMAKE_PREFIX_PATH $ENV{CMAKE_PREFIX_PATH})
-+endif()
-+
- if (DEFINED CMAKE_PREFIX_PATH)
-     file(TO_CMAKE_PATH "${CMAKE_PREFIX_PATH}" CMAKE_PREFIX_PATH)
- endif()