diff --git a/skimage/io/_plugins/freeimage_plugin.py b/skimage/io/_plugins/freeimage_plugin.py
index 6475781b..af611250 100644
--- a/skimage/io/_plugins/freeimage_plugin.py
+++ b/skimage/io/_plugins/freeimage_plugin.py
@@ -72,12 +72,12 @@ def load_freeimage():
             # No freeimage library loaded, and load-errors reported for some
             # candidate libs
             err_txt = ['%s:\n%s' % (l, str(e.message)) for l, e in errors]
-            raise OSError('One or more FreeImage libraries were found, but '
+            raise RuntimeError('One or more FreeImage libraries were found, but '
                           'could not be loaded due to the following errors:\n'
                           '\n\n'.join(err_txt))
         else:
             # No errors, because no potential libraries found at all!
-            raise OSError('Could not find a FreeImage library in any of:\n' +
+            raise RuntimeError('Could not find a FreeImage library in any of:\n' +
                           '\n'.join(lib_dirs))
 
     # FreeImage found
diff --git a/skimage/io/tests/test_freeimage.py b/skimage/io/tests/test_freeimage.py
index 565f37bd..7a294f9e 100644
--- a/skimage/io/tests/test_freeimage.py
+++ b/skimage/io/tests/test_freeimage.py
@@ -11,7 +11,7 @@ try:
     import skimage.io._plugins.freeimage_plugin as fi
     FI_available = True
     sio.use_plugin('freeimage')
-except OSError:
+except RuntimeError:
     FI_available = False
 
 
@@ -23,7 +23,7 @@ def setup_module(self):
     """
     try:
         sio.use_plugin('freeimage')
-    except OSError:
+    except RuntimeError:
         pass
 
 
diff --git a/skimage/io/tests/test_plugin.py b/skimage/io/tests/test_plugin.py
index 28d8c2b3..5d1febe4 100644
--- a/skimage/io/tests/test_plugin.py
+++ b/skimage/io/tests/test_plugin.py
@@ -15,7 +15,7 @@ try:
     io.use_plugin('freeimage')
     FI_available = True
     priority_plugin = 'freeimage'
-except OSError:
+except RuntimeError:
     FI_available = False