diff --git a/Gemfile.lock b/Gemfile.lock
index b8fe64a..8f13658 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -15,7 +15,7 @@ PATH
       opentelemetry-resource_detectors (= 0.19.1)
       opentelemetry-sdk (~> 1.0, >= 1.0.2)
       pickup (~> 0.0.11)
-      prometheus-client (~> 2.0)
+      prometheus-client (>= 2, < 4)
       puma (~> 5.0, >= 5.0.4)
       rack (~> 2.2)
       rake (~> 13.0)
@@ -70,9 +70,12 @@ GEM
     mustermann (1.1.1)
       ruby2_keywords (~> 0.0.1)
     net-ldap (0.17.0)
+    nio4r (2.5.8)
     nio4r (2.5.8-java)
     nokogiri (1.12.5-java)
       racc (~> 1.4)
+    nokogiri (1.12.5-x86_64-linux)
+      racc (~> 1.4)
     opentelemetry-api (1.0.1)
     opentelemetry-common (0.19.3)
       opentelemetry-api (~> 1.0)
@@ -112,13 +115,19 @@ GEM
     parser (3.1.0.0)
       ast (~> 2.4.1)
     pickup (0.0.11)
-    prometheus-client (2.1.0)
+    prometheus-client (3.0.0)
+    pry (0.14.1)
+      coderay (~> 1.1)
+      method_source (~> 1.0)
     pry (0.14.1-java)
       coderay (~> 1.1)
       method_source (~> 1.0)
       spoon (~> 0.0)
+    puma (5.5.2)
+      nio4r (~> 2.0)
     puma (5.5.2-java)
       nio4r (~> 2.0)
+    racc (1.6.0)
     racc (1.6.0-java)
     rack (2.2.3)
     rack-protection (2.1.0)
@@ -182,6 +191,7 @@ GEM
 
 PLATFORMS
   universal-java-1.8
+  x86_64-linux
 
 DEPENDENCIES
   climate_control (>= 0.2.0)
diff --git a/vmpooler.gemspec b/vmpooler.gemspec
index 49e2375..fdf13c1 100644
--- a/vmpooler.gemspec
+++ b/vmpooler.gemspec
@@ -30,7 +30,7 @@ Gem::Specification.new do |s|
   s.add_dependency 'opentelemetry-resource_detectors', '= 0.19.1'
   s.add_dependency 'opentelemetry-sdk', '~> 1.0', '>= 1.0.2'
   s.add_dependency 'pickup', '~> 0.0.11'
-  s.add_dependency 'prometheus-client', '~> 2.0'
+  s.add_dependency 'prometheus-client', '>= 2', '< 4'
   s.add_dependency 'puma', '~> 5.0', '>= 5.0.4'
   s.add_dependency 'rack', '~> 2.2'
   s.add_dependency 'rake', '~> 13.0'