diff --git a/.version b/.version
new file mode 100644
index 0000000..afaf360
--- /dev/null
+++ b/.version
@@ -0,0 +1 @@
+1.0.0
\ No newline at end of file
diff --git a/Makefile b/Makefile
index 8f48c83..9649427 100644
--- a/Makefile
+++ b/Makefile
@@ -53,15 +53,24 @@ MANPAGES  = $(addprefix $(SHAREDIR)/,gray.1 gray-convert.1 gray.ini.5 \
               profiles.txt.5 beamdata.txt.5 magneticdata.txt.5)
 
 ##
-## Git information (used in the version string)
+## Version information
 ##
 
+ifneq ($(wildcard .git/*),)
+# We are building from a git checkout
+
 # Short hash of the latest commit
-GIT_REV   ?= $(shell git rev-parse --short HEAD)
+GIT_REV ?= $(shell git rev-parse --short HEAD)
 
 # Whether the worktree and the latest commit differs
 GIT_DIRTY ?= $(shell test -n "$$(git status --porcelain)" && echo "-dirty")
 
+REVISION ?= $(GIT_REV)$(GIT_DIRTY)
+else
+# We are building from a release archive, use the version
+REVISION ?= v$(file < .version)
+endif
+
 # Source date
 ifndef SOURCE_DATE_EPOCH
 # Use current date
@@ -76,7 +85,7 @@ DATE=$(shell LC_TIME=C date -d @$(SOURCE_DATE_EPOCH) '+%B %Y')
 LD = $(FC)
 FFLAGS   += -I$(INCDIR) -fpic
 LDFLAGS  += -L$(LIBDIR)
-CPPFLAGS += -DREVISION=\"$(GIT_REV)$(GIT_DIRTY)\" -DPREFIX=\"$(PREFIX)\"
+CPPFLAGS += -DREVISION=\"$(REVISION)\" -DPREFIX=\"$(PREFIX)\"
 
 # Compiler-specific flags
 ifdef GNU
diff --git a/default.nix b/default.nix
index 98b8a01..cca5ff0 100644
--- a/default.nix
+++ b/default.nix
@@ -14,18 +14,19 @@ let
     sha256 = "007nv11r0z9fz593iwzn55nc0p0wj5lpgf0k2brhs1ynmikq9gjr";
   };
 
-  # Exclude this file and build artifacts
+  # Exclude this file, build artifacts and git
   source = builtins.filterSource
     (path: type:
       !builtins.elem path [ "configure.mk" "default.nix" "result" ]
-      && baseNameOf path != "build") ./.;
+      && baseNameOf path != "build"
+      && baseNameOf path != ".git") ./.;
 
   inherit (import nixpkgs {}) lib pkgs;
 
 in
   pkgs.stdenv.mkDerivation rec {
     pname = "gray";
-    version = "0.1";
+    version = builtins.readFile ./.version;
     src = source;
 
     doCheck = true;
@@ -72,8 +73,6 @@ in
       (lib.enableFeature static "static")
       "--with-katex=${katex}"
       "--enable-deterministic"
-      "GIT_REV=${version}"
-      "GIT_DIRTY="
     ];
 
     meta = {