diff --git a/gnu/packages/gnuzilla.scm b/gnu/packages/gnuzilla.scm
index f2de477548..99e534c05e 100644
--- a/gnu/packages/gnuzilla.scm
+++ b/gnu/packages/gnuzilla.scm
@@ -694,8 +694,8 @@ (define* (computed-origin-method gexp-promise hash-algo hash
                       #:system system
                       #:guile-for-build guile)))
 
-(define %icecat-version "78.9.0-guix0-preview1")
-(define %icecat-build-id "20210323000000") ;must be of the form YYYYMMDDhhmmss
+(define %icecat-version "78.10.0-guix0-preview1")
+(define %icecat-build-id "20210419000000") ;must be of the form YYYYMMDDhhmmss
 
 ;; 'icecat-source' is a "computed" origin that generates an IceCat tarball
 ;; from the corresponding upstream Firefox ESR tarball, using the 'makeicecat'
@@ -717,7 +717,7 @@ (define icecat-source
                   "firefox-" upstream-firefox-version ".source.tar.xz"))
             (sha256
              (base32
-              "0r28wrsk2k6pc922zfs5wljh8ziqm4a98lisn7409j2szhfsq0wf"))))
+              "0h6zl87czbhyhy3597bxqzwy4p1vsaqimkg92lw31gjbv6k434cp"))))
 
          (upstream-icecat-base-version "78.7.0") ; maybe older than base-version
          ;;(gnuzilla-commit (string-append "v" upstream-icecat-base-version))