diff --git a/Makefile b/Makefile
index bb341da..639c691 100644
--- a/Makefile
+++ b/Makefile
@@ -6,9 +6,10 @@ SYMLINK_PREFIX := library_
 # Docker registry variables
 REGISTRY := git.query.consul
 OWNER := unkin
-#GIT_COMMIT := $(shell git rev-parse --short HEAD)
 DATE_TAG := $(shell date +%Y%m%d)
-BRANCH=$(shell git branch --show-current)
+SUFFIX=$(shell basename $(mktemp -u) | cut -d . -f 2)
+GIT_BRANCH=$(shell git branch --show-current)
+GIT_COMMIT := $(shell git rev-parse --short HEAD)
 
 # Find all subdirectories under the IMAGES_PATH
 DIRS := $(shell find $(IMAGES_PATH) -mindepth 3 -maxdepth 3 -type d | sed 's|$(IMAGES_PATH)/||')
@@ -40,18 +41,19 @@ $(DIRS):
 	# Export environment
 	export VAULT_TOKEN=$$(vault write -field=token auth/approle/login role_id=$$VAULT_ROLEID)
 	export VAULT_ADDR=https://vault.service.consul:8200
-	@for kv in $$(vault kv get -format=json kv/service/packer/builder/env | jq -r '.data.data | to_entries[] | "\(.key)=\(.value)"'); do \
-		export "$kv"; \
-	done
+	@eval $$(vault kv get -format=json kv/service/packer/builder/env | jq -r '.data.data | to_entries[] | "export \(.key)=\(.value)"')
 
 	# Check if on master branch
-	@if [ "$(BRANCH)" = "master" ]; then \
-		echo "Current branch is $(BRANCH), checking latest timestamp in consul."; \
+	@if [ "$(GIT_BRANCH)" = "master" ]; then \
+		echo "Current branch is $(GIT_BRANCH), checking latest timestamp in consul."; \
 		LAST_BUILD_TIMESTAMP=$$(consul kv get infra/packer/$@/timestamp || echo "0"); \
 		CURRENT_TIME=$$(date +%s); \
 		if [ $$((CURRENT_TIME - LAST_BUILD_TIMESTAMP)) -lt 86400 ]; then \
-			echo "Skipping build for $@ (built within the last 24 hours)"; \
-			exit 0; \
+			LAST_COMMIT=$$(consul kv get infra/packer/$@/commit || echo "0"); \
+			if [ "$$((LAST_COMMIT))" == "$(GIT_COMMIT)" ]; then \
+				echo "Skipping build for $@. Same commit as last, and less than 24 hours since last build."; \
+				exit 0; \
+			fi; \
 		fi; \
 	fi
 
@@ -73,18 +75,20 @@ $(DIRS):
 	export DOCKER_SOURCE=$$OS_NAME:$$OS_VERSION_FULL && \
 	export DOCKER_SERVER='git.query.consul' && \
 	export INCUS_SOURCE="images:$$OS_NAME/$$OS_VERSION_MAJOR" && \
-	export SUFFIX=$$(basename $$(mktemp -u) | cut -d . -f 2) && \
-	export GIT_BRANCH=$(BRANCH) && \
+	export SUFFIX=$(SUFFIX) && \
+	export GIT_COMMIT=$(GIT_COMMIT) && \
+	export GIT_BRANCH=$(GIT_BRANCH) && \
 	packer init . && \
 	packer build . )
 
 	# Update build timestamp and date in Consul if on master branch
 	@if [ "$(BRANCH)" = "master" ]; then \
-		echo "Current branch is $(BRANCH), updating consul."; \
+		echo "Current branch is $(GIT_BRANCH), updating consul."; \
 		CURRENT_TIMESTAMP=$$(date +%s); \
 		READABLE_DATE=$$(date '+%Y-%m-%d %H:%M:%S %Z'); \
 		consul kv put infra/packer/$@/timestamp $$CURRENT_TIMESTAMP; \
 		consul kv put infra/packer/$@/date "$$READABLE_DATE"; \
+		consul kv put infra/packer/$@/commit "$$GIT_COMMIT"; \
 	fi
 
 # Clean all symlinks
diff --git a/library/variables.pkr.hcl b/library/variables.pkr.hcl
index f26fe58..9845aa9 100644
--- a/library/variables.pkr.hcl
+++ b/library/variables.pkr.hcl
@@ -111,6 +111,11 @@ variable "suffix" {
   type = string
   default = env("SUFFIX")
 }
+variable "git_commit" {
+  description = "The current git commit."
+  type = string
+  default = env("GIT_COMMIT")
+}
 variable "git_branch" {
   description = "The current git branch."
   type = string