diff --git a/problems/blast.in b/problems/blast.in
index 551ef8b..3c63d15 100644
--- a/problems/blast.in
+++ b/problems/blast.in
@@ -6,8 +6,8 @@ ratio                = 1.0000d+02
 radius               = 1.0000d-01
 buni                 = 0.0000d+00
 angle                = 4.5000d+01
-csnd                 = 4.0825d-01
-gamma                = 1.6667d+00
+sound_speed          = 4.0825d-01
+adiabatic_index      = 1.6667d+00
 
 # physics
 #
diff --git a/problems/implosion.in b/problems/implosion.in
index 11f94e6..5da46e0 100644
--- a/problems/implosion.in
+++ b/problems/implosion.in
@@ -1,7 +1,7 @@
 # problem name and parameters
 #
 problem               = "implosion"
-gamma                 =  1.40d+00
+adiabatic_index       =  1.40d+00
 shock_line            =  5.00d-01
 
 # physics
diff --git a/problems/rayleigh-taylor.in b/problems/rayleigh-taylor.in
index 3751bcf..b9f0b9d 100644
--- a/problems/rayleigh-taylor.in
+++ b/problems/rayleigh-taylor.in
@@ -1,7 +1,7 @@
 # problem name and parameters
 #
 problem              = "rayleigh-taylor"
-gamma                = 1.4d+00
+adiabatic_index      = 1.4d+00
 
 # random number generator parameters
 #
diff --git a/problems/sedov-taylor.in b/problems/sedov-taylor.in
index 990aae0..313124a 100644
--- a/problems/sedov-taylor.in
+++ b/problems/sedov-taylor.in
@@ -1,7 +1,7 @@
 # problem name and parameters
 #
 problem              = "sedov-taylor"
-gamma                = 1.4d+00
+adiabatic_index      = 1.4d+00
 
 # physics
 #