diff --git a/tools/plotting/fastnnlo_absolute.py b/tools/plotting/fastnnlo_absolute.py
index c6926ef7a7df1b2a5aa1daa582c212d53d7b443e..b15ccd341ca8b6e94791dad6264fb02048d7a9b5 100755
--- a/tools/plotting/fastnnlo_absolute.py
+++ b/tools/plotting/fastnnlo_absolute.py
@@ -510,5 +510,6 @@ for i in range(nscl):
             fignam = args['filename']+'.scl'+str(i+1)+'.absolute-index-'+str(ylim2)+'.png'
     if verb: print('[fastnnlo_absolute]: Writing figure: {:s}'.format(fignam))
     plt.savefig(fignam, bbox_inches='tight')
+    plt.close(fig)
 
 exit(0)
diff --git a/tools/plotting/fastnnlo_kfaccomp.py b/tools/plotting/fastnnlo_kfaccomp.py
index 003d1ec044c2f0c0dda4ac7ff20c62fcb0bd7d99..a029cff278ea81d23184359990fcd3c1abde5051 100755
--- a/tools/plotting/fastnnlo_kfaccomp.py
+++ b/tools/plotting/fastnnlo_kfaccomp.py
@@ -471,5 +471,6 @@ else:
 print('[fastnnlo_kfaccomp]: Writing figure {:s}'.format(fignam))
 
 plt.savefig(fignam)
+plt.close(fig)
 
 exit(0)
diff --git a/tools/plotting/fastnnlo_runtime.py b/tools/plotting/fastnnlo_runtime.py
index 8ce75a9cd15cfa25ce52d48bf411a993f38463bd..2d0b9ef00321b9d64ffe9f49f77a337a224f156d 100755
--- a/tools/plotting/fastnnlo_runtime.py
+++ b/tools/plotting/fastnnlo_runtime.py
@@ -330,6 +330,7 @@ def plot_elapsed_time(infodict, out_path, out_name, formats):
             filename += channels[0]  + '.' + basename + '.' + fmt
         print('[fastnnlo_runtime]: Saving runtime plot {}'.format(filename))
         fig.savefig(filename)
+    plt.close(fig)
 
 def plot_events_per_hour(infodict, out_path, out_name, formats):
 
@@ -428,6 +429,7 @@ def plot_events_per_hour(infodict, out_path, out_name, formats):
             filename += channels[0]  + '.' + basename + '.' + fmt
         print('[fastnnlo_runtime]: Saving event rate plot {}'.format(filename))
         fig.savefig(filename)
+    plt.close(fig)
 
 if __name__ == "__main__":
     main()
diff --git a/tools/plotting/fastnnlo_scaleclosure.py b/tools/plotting/fastnnlo_scaleclosure.py
index d274f5de0c1c7002b13ade3dced3b75f5fb4b595..82e80903c7c9330760327d662659095aff1725fe 100755
--- a/tools/plotting/fastnnlo_scaleclosure.py
+++ b/tools/plotting/fastnnlo_scaleclosure.py
@@ -475,5 +475,6 @@ for i in range(nscl):
     else:
         fignam = args['filename']+'.scl'+str(i+1)+'.scaleclosure-'+str(ylim2)+'.png'
     plt.savefig(fignam)
+    plt.close(fig)
 
 exit(0)