diff --git a/owlps-aggregator/Makefile b/owlps-aggregator/Makefile
index 74abb2a..e2d6985 100644
--- a/owlps-aggregator/Makefile
+++ b/owlps-aggregator/Makefile
@@ -1,6 +1,6 @@
 # Source version
 ifndef OWLPS_VERSION
-	OWLPS_VERSION = $$(git describe || echo 'UNKNOWN_VERSION')
+	OWLPS_VERSION := $(shell git describe 2>/dev/null || echo 'UNKNOWN_VERSION')
 endif
 
 # Répertoire d'installation
diff --git a/owlps-client/Makefile b/owlps-client/Makefile
index cfd82c2..accff24 100644
--- a/owlps-client/Makefile
+++ b/owlps-client/Makefile
@@ -1,6 +1,6 @@
 # Source version
 ifndef OWLPS_VERSION
-	OWLPS_VERSION = $$(git describe || echo 'UNKNOWN_VERSION')
+	OWLPS_VERSION := $(shell git describe 2>/dev/null || echo 'UNKNOWN_VERSION')
 endif
 
 # Répertoire d'installation
diff --git a/owlps-client/Makefile_atheros b/owlps-client/Makefile_atheros
index 8cb08e9..89fbb3c 100644
--- a/owlps-client/Makefile_atheros
+++ b/owlps-client/Makefile_atheros
@@ -1,6 +1,6 @@
 # Source version
 ifndef OWLPS_VERSION
-	OWLPS_VERSION = $$(git describe || echo 'UNKNOWN_VERSION')
+	OWLPS_VERSION := $(shell git describe 2>/dev/null || echo 'UNKNOWN_VERSION')
 endif
 
 # Emplacement de la suite de cross-compilation
diff --git a/owlps-client/Makefile_atheros_openwrt-10.03 b/owlps-client/Makefile_atheros_openwrt-10.03
index 9b57248..27545d2 100644
--- a/owlps-client/Makefile_atheros_openwrt-10.03
+++ b/owlps-client/Makefile_atheros_openwrt-10.03
@@ -1,6 +1,6 @@
 # Source version
 ifndef OWLPS_VERSION
-	OWLPS_VERSION = $$(git describe || echo 'UNKNOWN_VERSION')
+	OWLPS_VERSION := $(shell git describe 2>/dev/null || echo 'UNKNOWN_VERSION')
 endif
 
 # Emplacement de la suite de cross-compilation
diff --git a/owlps-listener/Makefile b/owlps-listener/Makefile
index fd217dd..1c7f66b 100644
--- a/owlps-listener/Makefile
+++ b/owlps-listener/Makefile
@@ -1,6 +1,6 @@
 # Source version
 ifndef OWLPS_VERSION
-	OWLPS_VERSION = $$(git describe || echo 'UNKNOWN_VERSION')
+	OWLPS_VERSION := $(shell git describe 2>/dev/null || echo 'UNKNOWN_VERSION')
 endif
 
 # Répertoire d'installation
diff --git a/owlps-listener/Makefile_atheros b/owlps-listener/Makefile_atheros
index 2604b04..bf5260e 100644
--- a/owlps-listener/Makefile_atheros
+++ b/owlps-listener/Makefile_atheros
@@ -1,6 +1,6 @@
 # Source version
 ifndef OWLPS_VERSION
-	OWLPS_VERSION = $$(git describe)
+	OWLPS_VERSION := $(shell git describe 2>/dev/null || echo 'UNKNOWN_VERSION')
 endif
 
 # Emplacement de la suite de cross-compilation
diff --git a/owlps-positioning/Makefile b/owlps-positioning/Makefile
index 5545c48..0e02bb2 100644
--- a/owlps-positioning/Makefile
+++ b/owlps-positioning/Makefile
@@ -1,6 +1,6 @@
 # Source version
 ifndef OWLPS_VERSION
-	OWLPS_VERSION = $$(git describe || echo 'UNKNOWN_VERSION')
+	OWLPS_VERSION := $(shell git describe 2>/dev/null || echo 'UNKNOWN_VERSION')
 endif
 
 # Directories & files