diff --git a/.github/workflows/linux.yaml b/.github/workflows/linux.yaml
index ea424ebe..a095c5b2 100644
--- a/.github/workflows/linux.yaml
+++ b/.github/workflows/linux.yaml
@@ -61,3 +61,13 @@ jobs:
           bundle exec ensure_arduino_installation.rb
           sh ./scripts/install.sh
           bundle exec arduino_ci.rb
+
+  SharedLibrary:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - uses: ruby/setup-ruby@v1
+        with:
+          ruby-version: 2.6
+      - name: Test SharedLibrary should fail
+        run: ./SampleProjects/SharedLibrary/test.sh
diff --git a/.github/workflows/macos.yaml b/.github/workflows/macos.yaml
index 8b51fd60..5019f96f 100644
--- a/.github/workflows/macos.yaml
+++ b/.github/workflows/macos.yaml
@@ -61,3 +61,13 @@ jobs:
           bundle exec ensure_arduino_installation.rb
           sh ./scripts/install.sh
           bundle exec arduino_ci.rb
+
+  SharedLibrary:
+    runs-on: macos-latest
+    steps:
+      - uses: actions/checkout@v2
+      - uses: ruby/setup-ruby@v1
+        with:
+          ruby-version: 2.6
+      - name: Test SharedLibrary should fail
+        run: ./SampleProjects/SharedLibrary/test.sh
diff --git a/.github/workflows/windows.yaml b/.github/workflows/windows.yaml
index 3a40eed3..3169ea44 100644
--- a/.github/workflows/windows.yaml
+++ b/.github/workflows/windows.yaml
@@ -50,3 +50,13 @@ jobs:
           bundle exec ensure_arduino_installation.rb
           bash -x ./scripts/install.sh
           bundle exec arduino_ci.rb
+
+  SharedLibrary:
+    runs-on: windows-latest
+    steps:
+      - uses: actions/checkout@v2
+      - uses: ruby/setup-ruby@v1
+        with:
+          ruby-version: 2.6
+      - name: Test SharedLibrary should fail
+        run: ./SampleProjects/SharedLibrary/test.sh
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 51216f91..16ee831b 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -32,6 +32,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 - Fix copy/paste error to allow additional warnings for a platform
 - Apply "rule of three" to Client copy constructor and copy assignment operator
 - Run Windows tests on Windows not Ubuntu
+- Properly report error in building shared library
 
 ### Security
 
diff --git a/SampleProjects/SharedLibrary/.arduino-ci.yml b/SampleProjects/SharedLibrary/.arduino-ci.yml
new file mode 100644
index 00000000..f63d2413
--- /dev/null
+++ b/SampleProjects/SharedLibrary/.arduino-ci.yml
@@ -0,0 +1,7 @@
+unittest:
+  platforms:
+    - mega2560
+
+compile:
+  platforms:
+    - mega2560
diff --git a/SampleProjects/SharedLibrary/.gitignore b/SampleProjects/SharedLibrary/.gitignore
new file mode 100644
index 00000000..06de90aa
--- /dev/null
+++ b/SampleProjects/SharedLibrary/.gitignore
@@ -0,0 +1 @@
+.bundle
\ No newline at end of file
diff --git a/SampleProjects/SharedLibrary/Gemfile b/SampleProjects/SharedLibrary/Gemfile
new file mode 100644
index 00000000..b2b3b1fd
--- /dev/null
+++ b/SampleProjects/SharedLibrary/Gemfile
@@ -0,0 +1,2 @@
+source 'https://rubygems.org'
+gem 'arduino_ci', path: '../../'
diff --git a/SampleProjects/SharedLibrary/README.md b/SampleProjects/SharedLibrary/README.md
new file mode 100644
index 00000000..40e8645c
--- /dev/null
+++ b/SampleProjects/SharedLibrary/README.md
@@ -0,0 +1,3 @@
+# SharedLibrary
+
+This is an example of a shared library with a compile error (see https://github.com/Arduino-CI/arduino_ci/issues/325).
diff --git a/SampleProjects/SharedLibrary/library.properties b/SampleProjects/SharedLibrary/library.properties
new file mode 100644
index 00000000..5f9d3662
--- /dev/null
+++ b/SampleProjects/SharedLibrary/library.properties
@@ -0,0 +1,10 @@
+name=SharedLibrary
+version=0.1.0
+author=James Foster <arduino@jgfoster.net>
+maintainer=James Foster <arduino@jgfoster.net>
+sentence=Sample shared library to validate that we catch compile errors
+paragraph=Sample shared library to validate that we catch compile errors
+category=Other
+url=https://github.com/Arduino-CI/arduino_ci/SampleProjects/SharedLibrary
+architectures=avr,esp8266
+includes=SharedLibrary.h
diff --git a/SampleProjects/SharedLibrary/src/SharedLibrary.cpp b/SampleProjects/SharedLibrary/src/SharedLibrary.cpp
new file mode 100644
index 00000000..347aaf17
--- /dev/null
+++ b/SampleProjects/SharedLibrary/src/SharedLibrary.cpp
@@ -0,0 +1,5 @@
+#include "SharedLibrary.h"
+
+int main() {
+  return foo; // 'foo' was not declared in this scope
+}
diff --git a/SampleProjects/SharedLibrary/src/SharedLibrary.h b/SampleProjects/SharedLibrary/src/SharedLibrary.h
new file mode 100644
index 00000000..9ee81b24
--- /dev/null
+++ b/SampleProjects/SharedLibrary/src/SharedLibrary.h
@@ -0,0 +1,3 @@
+#pragma once
+
+#include <Arduino.h>
diff --git a/SampleProjects/SharedLibrary/test.sh b/SampleProjects/SharedLibrary/test.sh
new file mode 100755
index 00000000..b5ab6e4b
--- /dev/null
+++ b/SampleProjects/SharedLibrary/test.sh
@@ -0,0 +1,9 @@
+g++ -v
+cd SampleProjects/SharedLibrary
+bundle install
+bundle exec ensure_arduino_installation.rb
+bundle exec arduino_ci.rb --skip-examples-compilation
+if [ $? -ne 1 ]; then
+  exit 1
+fi
+exit 0
diff --git a/SampleProjects/SharedLibrary/test/test.cpp b/SampleProjects/SharedLibrary/test/test.cpp
new file mode 100644
index 00000000..326c978e
--- /dev/null
+++ b/SampleProjects/SharedLibrary/test/test.cpp
@@ -0,0 +1,13 @@
+/*
+cd SampleProjects/SharedLibrary
+bundle config --local path vendor/bundle
+bundle install
+bundle exec arduino_ci.rb --skip-examples-compilation
+*/
+
+#include <Arduino.h>
+#include <ArduinoUnitTests.h>
+
+unittest(test) { assertEqual(true, true); }
+
+unittest_main()
diff --git a/exe/arduino_ci.rb b/exe/arduino_ci.rb
index ebaa1452..175cdb2c 100755
--- a/exe/arduino_ci.rb
+++ b/exe/arduino_ci.rb
@@ -423,7 +423,22 @@ def perform_unit_tests(cpp_library, file_config)
     puts
     compilers.each do |gcc_binary|
       # before compiling the tests, build a shared library of everything except the test code
-      next unless build_shared_library(gcc_binary, p, config, cpp_library)
+      got_shared_library = true
+      attempt_multiline("Build shared library with #{gcc_binary} for #{p}") do
+        exe = cpp_library.build_shared_library(
+          config.aux_libraries_for_unittest,
+          gcc_binary,
+          config.gcc_config(p)
+        )
+        unless exe
+          puts "Last command: #{cpp_library.last_cmd}"
+          puts cpp_library.last_out
+          puts cpp_library.last_err
+          got_shared_library = false
+        end
+        next got_shared_library
+      end
+      next unless got_shared_library
 
       # now build and run each test using the shared library build above
       config.allowable_unittest_files(cpp_library.test_files).each do |unittest_path|
@@ -445,24 +460,6 @@ def perform_unit_tests(cpp_library, file_config)
   end
 end
 
-def build_shared_library(gcc_binary, platform, config, cpp_library)
-  attempt_multiline("Build shared library with #{gcc_binary} for #{platform}") do
-    exe = cpp_library.build_shared_library(
-      config.aux_libraries_for_unittest,
-      gcc_binary,
-      config.gcc_config(platform)
-    )
-    puts
-    unless exe
-      puts "Last command: #{cpp_library.last_cmd}"
-      puts cpp_library.last_out
-      puts cpp_library.last_err
-      return false
-    end
-    return true
-  end
-end
-
 def perform_example_compilation_tests(cpp_library, config)
   phase("Compilation of example sketches")
   if @cli_options[:skip_compilation]