diff --git a/pkgs/development/interpreters/unicon-lang/default.nix b/pkgs/development/interpreters/unicon-lang/default.nix
index 6d7088a11cb..848c9541114 100644
--- a/pkgs/development/interpreters/unicon-lang/default.nix
+++ b/pkgs/development/interpreters/unicon-lang/default.nix
@@ -14,6 +14,13 @@ stdenv.mkDerivation {
 
   sourceRoot = ".";
 
+  # Workaround build failure on -fno-common toolchains like upstream
+  # gcc-10. Otherwise build fails as:
+  #   ld: ../common/ipp.o:(.bss+0x0): multiple definition of `lpath'; tglobals.o:(.bss+0x30): first defined here
+  # TODO: remove the workaround once upstream releases version past:
+  #   https://sourceforge.net/p/unicon/unicon/ci/b1a65230233f3825d055aee913b4fdcf178a0eaf/
+  NIX_CFLAGS_COMPILE = "-fcommon";
+
   configurePhase = ''
     case "$(uname -a | sed 's/ /_/g')" in
     Darwin*Version_9*i386) sys=intel_macos;;