diff --git a/README.md b/README.md
index 98e1b58..810e3ef 100644
--- a/README.md
+++ b/README.md
@@ -130,6 +130,9 @@ should be a `;` sperated list of `key=value` pairs. The possible keys are
 * `keep_en_cst` (0 or 1, default 0): impose that the enstrophy is constant at
   each step (only really useful for the reversible equation).
 
+* `print_alpha` (0 or 1, default 0): if this is set to 1, then whenever alpha
+  is negative, its value is printed as a comment.
+
 
 # Interrupting and resuming the computation
 
diff --git a/src/main.c b/src/main.c
index 6b5079e..eebdaca 100644
--- a/src/main.c
+++ b/src/main.c
@@ -58,6 +58,7 @@ typedef struct nstrophy_parameters {
   FILE* drivingfile;
   double lyapunov_reset;
   double D_epsilon;
+  bool print_alpha;
 } nstrophy_parameters;
 
 // usage message
@@ -277,7 +278,7 @@ int main (
     // register signal handler to handle aborts
     signal(SIGINT, sig_handler);
     signal(SIGTERM, sig_handler);
-    enstrophy(parameters.K1, parameters.K2, parameters.N1, parameters.N2, parameters.final_time, parameters.nu, parameters.delta, parameters.L, parameters.adaptive_tolerance, parameters.adaptive_factor, parameters.max_delta, parameters.adaptive_norm, u0, g, parameters.irreversible, parameters.keep_en_cst, parameters.init_en, parameters.algorithm, parameters.print_freq, parameters.starting_time, nthreads, savefile, utfile, (char*)argv[0], dstring_to_str_noinit(&param_str), dstring_to_str_noinit(&savefile_str), dstring_to_str_noinit(&utfile_str));
+    enstrophy(parameters.K1, parameters.K2, parameters.N1, parameters.N2, parameters.final_time, parameters.nu, parameters.delta, parameters.L, parameters.adaptive_tolerance, parameters.adaptive_factor, parameters.max_delta, parameters.adaptive_norm, u0, g, parameters.irreversible, parameters.keep_en_cst, parameters.init_en, parameters.algorithm, parameters.print_freq, parameters.starting_time, parameters.print_alpha, nthreads, savefile, utfile, (char*)argv[0], dstring_to_str_noinit(&param_str), dstring_to_str_noinit(&savefile_str), dstring_to_str_noinit(&utfile_str));
   }
   else if(command==COMMAND_QUIET){
     quiet(parameters.K1, parameters.K2, parameters.N1, parameters.N2, parameters.final_time, parameters.nu, parameters.delta, parameters.L, parameters.adaptive_tolerance, parameters.adaptive_factor, parameters.max_delta, parameters.adaptive_norm, parameters.starting_time, u0, g, parameters.irreversible, parameters.keep_en_cst, parameters.init_en, parameters.algorithm, nthreads, savefile);
@@ -554,6 +555,8 @@ int set_default_params(
   parameters->initfile=NULL;
   parameters->algorithm=ALGORITHM_RK4;
   parameters->keep_en_cst=false;
+
+  parameters->print_alpha=false;
   
   return(0);
 }
@@ -885,6 +888,15 @@ int set_parameter(
     }
     parameters->keep_en_cst=(tmp==1);
   }
+  else if (strcmp(lhs,"print_alpha")==0){
+    int tmp;
+    ret=sscanf(rhs,"%d",&tmp);
+    if(ret!=1 || (tmp!=0 && tmp!=1)){
+      fprintf(stderr, "error: parameter 'print_alpha' should be 0 or 1\n       got '%s'\n",rhs);
+      return(-1);
+    }
+    parameters->print_alpha=(tmp==1);
+  }
   else{
     fprintf(stderr, "error: unrecognized parameter '%s'\n",lhs);
     return(-1);
diff --git a/src/navier-stokes.c b/src/navier-stokes.c
index 8b68506..476ec4e 100644
--- a/src/navier-stokes.c
+++ b/src/navier-stokes.c
@@ -145,6 +145,7 @@ int enstrophy(
   unsigned int algorithm,
   double print_freq,
   double starting_time,
+  bool print_alpha,
   unsigned int nthreads,
   FILE* savefile,
   FILE* utfile,
@@ -236,7 +237,7 @@ int enstrophy(
     }
 
     // print alpha when it gets negative
-    if(alpha<0){
+    if(print_alpha && alpha<0){
       fprintf(stderr,"## negative alpha: % .8e at time % .8e\n",alpha, time);
       printf("## negative alpha: % .15e at time % .15e\n",alpha, time);
     }
diff --git a/src/navier-stokes.h b/src/navier-stokes.h
index 8c7e87b..9d9f989 100644
--- a/src/navier-stokes.h
+++ b/src/navier-stokes.h
@@ -34,7 +34,7 @@ typedef struct fft_vects {
 int uk( int K1, int K2, int N1, int N2, double final_time, double nu, double delta, double L, double adaptive_tolerance, double adaptive_factor, double max_delta, unsigned int adaptive_norm, _Complex double* u0, _Complex double* g, bool irreversible, bool keep_en_cst, double target_en, unsigned int algorithm, double print_freq, double starting_time, unsigned int nthreadsl, FILE* savefile);
 
 // compute enstrophy and alpha
-int enstrophy( int K1, int K2, int N1, int N2, double final_time, double nu, double delta, double L, double adaptive_tolerance, double adaptive_factor, double max_delta, unsigned int adaptive_norm, _Complex double* u0, _Complex double* g, bool irreversible, bool keep_en_cst, double target_en, unsigned int algorithm, double print_freq, double starting_time, unsigned int nthreads, FILE* savefile, FILE* utfile, const char* cmd_string, const char* params_string, const char* savefile_string, const char* utfile_string);
+int enstrophy( int K1, int K2, int N1, int N2, double final_time, double nu, double delta, double L, double adaptive_tolerance, double adaptive_factor, double max_delta, unsigned int adaptive_norm, _Complex double* u0, _Complex double* g, bool irreversible, bool keep_en_cst, double target_en, unsigned int algorithm, double print_freq, double starting_time, bool print_alpha, unsigned int nthreads, FILE* savefile, FILE* utfile, const char* cmd_string, const char* params_string, const char* savefile_string, const char* utfile_string);
 
 // compute solution as a function of time, but do not print anything (useful for debugging)
 int quiet( int K1, int K2, int N1, int N2, double final_time, double nu, double delta, double L, double adaptive_tolerance, double adaptive_factor, double max_delta, unsigned int adaptive_norm, double starting_time, _Complex double* u0, _Complex double* g, bool irreversible, bool keep_en_cst, double target_en, unsigned int algorithm, unsigned int nthreads, FILE* savefile);