diff --git a/lib/gpu/lal_hippo.cu b/lib/gpu/lal_hippo.cu
index 487e852baf..f643f2b994 100644
--- a/lib/gpu/lal_hippo.cu
+++ b/lib/gpu/lal_hippo.cu
@@ -1692,19 +1692,10 @@ __kernel void k_hippo_polar(const __global numtyp4 *restrict x_,
   if (ii<inum) {
     int k,m,itype,igroup;
     numtyp bfac;
-    numtyp psc3,psc5,psc7;
-    numtyp dsc3,dsc5,dsc7;
-    numtyp usc3,usc5;
-    numtyp psr3,psr5,psr7;
-    numtyp dsr3,dsr5,dsr7;
-    numtyp usr5;
     numtyp term1,term2,term3;
     numtyp term4,term5;
     numtyp term6,term7;
     numtyp rc3[3],rc5[3],rc7[3];
-    numtyp prc3[3],prc5[3],prc7[3];
-    numtyp drc3[3],drc5[3],drc7[3];
-    numtyp urc3[3],urc5[3];
     numtyp bn[5];
     numtyp ci,uix,uiy,uiz,uixp,uiyp,uizp;
 
@@ -1801,11 +1792,6 @@ __kernel void k_hippo_polar(const __global numtyp4 *restrict x_,
       numtyp factor_wscale, factor_dscale, factor_pscale, factor_uscale;
       const numtyp4 sp_pol = sp_polar[sbmask15(jextra)];
       factor_wscale = sp_pol.x; // special_polar_wscale[sbmask15(jextra)];
-      // NOTE: for in.water_box/water_hexamer.hippo: there exist wscale = 0.2
-      //if (factor_wscale < (numtyp)1.0) continue; //factor_wscale = (numtyp)0;
-
-      //if (i == 12 && j < 20) printf("j = %d: r = %f; factor_wscale = %f\n", j, r, factor_wscale);
-
       if (igroup == jgroup) {
         factor_dscale = factor_pscale = sp_pol.y; // special_polar_piscale[sbmask15(jextra)];
         factor_uscale = polar_uscale;
diff --git a/lib/gpu/lal_hippo_extra.h b/lib/gpu/lal_hippo_extra.h
index cacee4ae72..61bfebc17f 100644
--- a/lib/gpu/lal_hippo_extra.h
+++ b/lib/gpu/lal_hippo_extra.h
@@ -404,10 +404,10 @@ ucl_inline void dampmut(numtyp r, numtyp alphai, numtyp alphak, numtyp dmpik[5])
   if (diff < eps) {
     dampi4 = dampi2 * dampi2;
     dampi5 = dampi2 * dampi3;
-    dmpik[2] = 1.0 - (1.0 + dampi + 0.5*dampi2 + 
-                      7.0*dampi3/48.0 + dampi4/48.0)*expi;
-    dmpik[4] = 1.0 - (1.0 + dampi + 0.5*dampi2 + dampi3/6.0 + 
-                      dampi4/24.0 + dampi5/144.0)*expi;
+    dmpik[2] = (numtyp)1.0 - ((numtyp)1.0 + dampi + (numtyp)0.5*dampi2 + 
+                      7.0*dampi3/(numtyp)48.0 + dampi4/48.0)*expi;
+    dmpik[4] = (numtyp)1.0 - ((numtyp)1.0 + dampi + (numtyp)0.5*dampi2 + dampi3/(numtyp)6.0 + 
+                      dampi4/(numtyp)24.0 + dampi5/(numtyp)144.0)*expi;
   } else {
     dampk2 = dampk * dampk;
     dampk3 = dampk * dampk2;
@@ -417,13 +417,13 @@ ucl_inline void dampmut(numtyp r, numtyp alphai, numtyp alphak, numtyp dmpik[5])
     termk = alphai2 / (alphai2-alphak2);
     termi2 = termi * termi;
     termk2 = termk * termk;
-    dmpik[2] = 1.0 - termi2*(1.0+dampi+0.5*dampi2)*expi - 
-      termk2*(1.0+dampk+0.5*dampk2)*expk - 
-      2.0*termi2*termk*(1.0+dampi)*expi - 2.0*termk2*termi*(1.0+dampk)*expk;
-    dmpik[4] = 1.0 - termi2*(1.0+dampi+0.5*dampi2 + dampi3/6.0)*expi - 
-      termk2*(1.0+dampk+0.5*dampk2 + dampk3/6.00)*expk - 
-      2.0*termi2*termk *(1.0+dampi+dampi2/3.0)*expi - 
-      2.0*termk2*termi *(1.0+dampk+dampk2/3.0)*expk;
+    dmpik[2] = (numtyp)1.0 - termi2*((numtyp)1.0+dampi+(numtyp)0.5*dampi2)*expi - 
+      termk2*((numtyp)1.0+dampk+(numtyp)0.5*dampk2)*expk - 
+      (numtyp)2.0*termi2*termk*((numtyp)1.0+dampi)*expi - (numtyp)2.0*termk2*termi*((numtyp)1.0+dampk)*expk;
+    dmpik[4] = (numtyp)1.0 - termi2*((numtyp)1.0+dampi+(numtyp)0.5*dampi2 + dampi3/(numtyp)6.0)*expi - 
+      termk2*((numtyp)1.0+dampk+(numtyp)0.5*dampk2 + dampk3/(numtyp)6.00)*expk - 
+      (numtyp)2.0*termi2*termk *((numtyp)1.0+dampi+dampi2/(numtyp)3.0)*expi - 
+      (numtyp)2.0*termk2*termi *((numtyp)1.0+dampk+dampk2/(numtyp)3.0)*expk;
   }
 }