diff --git a/src/ROCKparams.cpp b/src/ROCKparams.cpp
index 57f11c01b9ebbf8802715fc87792ee808fbb9967..a7d496dfa9745acab1436fac765ef9548d783185 100755
--- a/src/ROCKparams.cpp
+++ b/src/ROCKparams.cpp
@@ -258,6 +258,7 @@ void ROCKparams::initFromMainOptsArgs(int argc,char ** argv) {
     std::vector<string> v_input_lines;
     std::vector<string> v_output_lines;
     static int PE_separately=1;
+    float proba=k_max_collision_proba;
 
     while((i = getopt(argc, argv, "i:o:l:k:c:C:n:vq:m:f:")) != -1) {
         switch(i) {
@@ -268,7 +269,7 @@ void ROCKparams::initFromMainOptsArgs(int argc,char ** argv) {
             case 'c':
                 parms.kappa_prime=atoi(optarg);break;
             case 'f':
-            	float proba=atof(optarg);
+            	proba=atof(optarg);
             	if ((proba<=0.0) or (proba>=1.0)) {
             		cout<<"maximum for collision probability in the CMS must be > 0.0 and <1.0."<<endl;
             		usage(EXIT_FAILURE);
@@ -319,7 +320,6 @@ void ROCKparams::initFromMainOptsArgs(int argc,char ** argv) {
                     cout<<"minimum number of valid k-mer for keeping a read must be an integer >=1"<<endl;
                     usage(EXIT_FAILURE);
                 }
-
                 qual_thres.min_correct_k_mers_in_read=atoi(optarg);
                 break;
             default: