diff --git a/build.gradle b/build.gradle
index d6b3b4faf..dc8f4b370 100644
--- a/build.gradle
+++ b/build.gradle
@@ -208,10 +208,10 @@ jar {
     manifest {
         attributes 'Specification-Title'   : 'picocli',
                    'Specification-Vendor'  : 'Remko Popma',
-                   'Specification-Version' : archiveVersion,
+                   'Specification-Version' : archiveVersion.get(),
                    'Implementation-Title'  : 'picocli',
                    'Implementation-Vendor' : 'Remko Popma',
-                   'Implementation-Version': archiveVersion,
+                   'Implementation-Version': archiveVersion.get(),
                    'Main-Class'            : 'picocli.AutoComplete'
     }
     // copy module-info.class to META-INF/versions/9
diff --git a/picocli-annotation-processing-tests/build.gradle b/picocli-annotation-processing-tests/build.gradle
index bac59d395..fd59a44c1 100644
--- a/picocli-annotation-processing-tests/build.gradle
+++ b/picocli-annotation-processing-tests/build.gradle
@@ -25,10 +25,10 @@ jar {
     manifest {
         attributes 'Specification-Title': 'Picocli Annotation Processing Tests',
                 'Specification-Vendor'  : 'Remko Popma',
-                'Specification-Version' : archiveVersion,
+                'Specification-Version' : archiveVersion.get(),
                 'Implementation-Title'  : 'Picocli Annotation Processing Tests',
                 'Implementation-Vendor' : 'Remko Popma',
-                'Implementation-Version': archiveVersion,
+                'Implementation-Version': archiveVersion.get(),
                 'Automatic-Module-Name' : 'info.picocli.annotation.processing.tests'
     }
 }
diff --git a/picocli-codegen/build.gradle b/picocli-codegen/build.gradle
index 584204dbf..b55fbadf4 100644
--- a/picocli-codegen/build.gradle
+++ b/picocli-codegen/build.gradle
@@ -36,10 +36,10 @@ jar {
     manifest {
         attributes 'Specification-Title'   : 'Picocli Code Generation',
                    'Specification-Vendor'  : 'Remko Popma',
-                   'Specification-Version' : archiveVersion,
+                   'Specification-Version' : archiveVersion.get(),
                    'Implementation-Title'  : 'Picocli Code Generation',
                    'Implementation-Vendor' : 'Remko Popma',
-                   'Implementation-Version': archiveVersion,
+                   'Implementation-Version': archiveVersion.get(),
                    'Automatic-Module-Name' : 'info.picocli.codegen'
     }
 }
diff --git a/picocli-groovy/build.gradle b/picocli-groovy/build.gradle
index b049d382a..7a9b83140 100644
--- a/picocli-groovy/build.gradle
+++ b/picocli-groovy/build.gradle
@@ -36,10 +36,10 @@ jar {
     manifest {
         attributes  'Specification-Title'   : 'Picocli Groovy',
                     'Specification-Vendor'  : 'Remko Popma',
-                    'Specification-Version' : archiveVersion,
+                    'Specification-Version' : archiveVersion.get(),
                     'Implementation-Title'  : 'Picocli Groovy',
                     'Implementation-Vendor' : 'Remko Popma',
-                    'Implementation-Version': archiveVersion,
+                    'Implementation-Version': archiveVersion.get(),
                     'Automatic-Module-Name' : 'info.picocli.groovy'
     }
 }
diff --git a/picocli-shell-jline2/build.gradle b/picocli-shell-jline2/build.gradle
index 422f38e17..67129c902 100644
--- a/picocli-shell-jline2/build.gradle
+++ b/picocli-shell-jline2/build.gradle
@@ -19,10 +19,10 @@ jar {
     manifest {
         attributes  'Specification-Title'   : 'Picocli Shell JLine2',
                     'Specification-Vendor'  : 'Remko Popma',
-                    'Specification-Version' : archiveVersion,
+                    'Specification-Version' : archiveVersion.get(),
                     'Implementation-Title'  : 'Picocli Shell JLine2',
                     'Implementation-Vendor' : 'Remko Popma',
-                    'Implementation-Version': archiveVersion,
+                    'Implementation-Version': archiveVersion.get(),
                     'Automatic-Module-Name' : 'info.picocli.shell.jline2'
     }
 }
diff --git a/picocli-shell-jline3/build.gradle b/picocli-shell-jline3/build.gradle
index 3cd562e59..b0f4e199b 100644
--- a/picocli-shell-jline3/build.gradle
+++ b/picocli-shell-jline3/build.gradle
@@ -22,10 +22,10 @@ jar {
     manifest {
         attributes  'Specification-Title'   : 'Picocli Shell JLine3',
                     'Specification-Vendor'  : 'Remko Popma',
-                    'Specification-Version' : archiveVersion,
+                    'Specification-Version' : archiveVersion.get(),
                     'Implementation-Title'  : 'Picocli Shell JLine3',
                     'Implementation-Vendor' : 'Remko Popma',
-                    'Implementation-Version': archiveVersion,
+                    'Implementation-Version': archiveVersion.get(),
                     'Automatic-Module-Name' : 'info.picocli.shell.jline3'
     }
 }
diff --git a/picocli-spring-boot-starter/build.gradle b/picocli-spring-boot-starter/build.gradle
index 19e233329..73aca3854 100644
--- a/picocli-spring-boot-starter/build.gradle
+++ b/picocli-spring-boot-starter/build.gradle
@@ -25,10 +25,10 @@ jar {
     manifest {
         attributes  'Specification-Title'   : 'Picocli Spring Boot Starter',
                     'Specification-Vendor'  : 'Remko Popma',
-                    'Specification-Version' : archiveVersion,
+                    'Specification-Version' : archiveVersion.get(),
                     'Implementation-Title'  : 'Picocli Spring Boot Starter',
                     'Implementation-Vendor' : 'Remko Popma',
-                    'Implementation-Version': archiveVersion,
+                    'Implementation-Version': archiveVersion.get(),
                     'Automatic-Module-Name' : 'info.picocli.spring'
     }
 }