diff --git a/dragonflybsd/DragonFlyBSDProcess.c b/dragonflybsd/DragonFlyBSDProcess.c
index 4c231093..517fc2a1 100644
--- a/dragonflybsd/DragonFlyBSDProcess.c
+++ b/dragonflybsd/DragonFlyBSDProcess.c
@@ -25,7 +25,7 @@ const ProcessClass DragonFlyBSDProcess_class = {
       .delete = Process_delete,
       .compare = DragonFlyBSDProcess_compare
    },
-   .writeField = (Process_WriteField) DragonFlyBSDProcess_writeField,
+   .writeField = DragonFlyBSDProcess_writeField,
 };
 
 ProcessFieldData Process_fields[] = {
@@ -83,8 +83,8 @@ void Process_delete(Object* cast) {
    free(this);
 }
 
-void DragonFlyBSDProcess_writeField(Process* this, RichString* str, ProcessField field) {
-   DragonFlyBSDProcess* fp = (DragonFlyBSDProcess*) this;
+void DragonFlyBSDProcess_writeField(const Process* this, RichString* str, ProcessField field) {
+   const DragonFlyBSDProcess* fp = (const DragonFlyBSDProcess*) this;
    char buffer[256]; buffer[255] = '\0';
    int attr = CRT_colors[DEFAULT_COLOR];
    int n = sizeof(buffer) - 1;
diff --git a/dragonflybsd/DragonFlyBSDProcess.h b/dragonflybsd/DragonFlyBSDProcess.h
index 1c048143..92e1dde2 100644
--- a/dragonflybsd/DragonFlyBSDProcess.h
+++ b/dragonflybsd/DragonFlyBSDProcess.h
@@ -37,7 +37,7 @@ DragonFlyBSDProcess* DragonFlyBSDProcess_new(Settings* settings);
 
 void Process_delete(Object* cast);
 
-void DragonFlyBSDProcess_writeField(Process* this, RichString* str, ProcessField field);
+void DragonFlyBSDProcess_writeField(const Process* this, RichString* str, ProcessField field);
 
 long DragonFlyBSDProcess_compare(const void* v1, const void* v2);
 
diff --git a/freebsd/FreeBSDProcess.c b/freebsd/FreeBSDProcess.c
index 71019494..684f4dfe 100644
--- a/freebsd/FreeBSDProcess.c
+++ b/freebsd/FreeBSDProcess.c
@@ -24,7 +24,7 @@ const ProcessClass FreeBSDProcess_class = {
       .delete = Process_delete,
       .compare = FreeBSDProcess_compare
    },
-   .writeField = (Process_WriteField) FreeBSDProcess_writeField,
+   .writeField = FreeBSDProcess_writeField,
 };
 
 ProcessFieldData Process_fields[] = {
@@ -83,8 +83,8 @@ void Process_delete(Object* cast) {
    free(this);
 }
 
-void FreeBSDProcess_writeField(Process* this, RichString* str, ProcessField field) {
-   FreeBSDProcess* fp = (FreeBSDProcess*) this;
+void FreeBSDProcess_writeField(const Process* this, RichString* str, ProcessField field) {
+   const FreeBSDProcess* fp = (const FreeBSDProcess*) this;
    char buffer[256]; buffer[255] = '\0';
    int attr = CRT_colors[DEFAULT_COLOR];
    int n = sizeof(buffer) - 1;
diff --git a/freebsd/FreeBSDProcess.h b/freebsd/FreeBSDProcess.h
index 36657060..d7b40101 100644
--- a/freebsd/FreeBSDProcess.h
+++ b/freebsd/FreeBSDProcess.h
@@ -43,7 +43,7 @@ FreeBSDProcess* FreeBSDProcess_new(Settings* settings);
 
 void Process_delete(Object* cast);
 
-void FreeBSDProcess_writeField(Process* this, RichString* str, ProcessField field);
+void FreeBSDProcess_writeField(const Process* this, RichString* str, ProcessField field);
 
 long FreeBSDProcess_compare(const void* v1, const void* v2);
 
diff --git a/linux/LinuxProcess.c b/linux/LinuxProcess.c
index 8003157c..b53692d8 100644
--- a/linux/LinuxProcess.c
+++ b/linux/LinuxProcess.c
@@ -135,7 +135,7 @@ const ProcessClass LinuxProcess_class = {
       .delete = Process_delete,
       .compare = LinuxProcess_compare
    },
-   .writeField = (Process_WriteField) LinuxProcess_writeField,
+   .writeField = LinuxProcess_writeField,
 };
 
 LinuxProcess* LinuxProcess_new(Settings* settings) {
@@ -197,8 +197,8 @@ void LinuxProcess_printDelay(float delay_percent, char* buffer, int n) {
 }
 #endif
 
-void LinuxProcess_writeField(Process* this, RichString* str, ProcessField field) {
-   LinuxProcess* lp = (LinuxProcess*) this;
+void LinuxProcess_writeField(const Process* this, RichString* str, ProcessField field) {
+   const LinuxProcess* lp = (const LinuxProcess*) this;
    bool coloring = this->settings->highlightMegabytes;
    char buffer[256]; buffer[255] = '\0';
    int attr = CRT_colors[DEFAULT_COLOR];
diff --git a/linux/LinuxProcess.h b/linux/LinuxProcess.h
index 8e7c36dc..bb0c5ebb 100644
--- a/linux/LinuxProcess.h
+++ b/linux/LinuxProcess.h
@@ -189,7 +189,7 @@ bool LinuxProcess_setIOPriority(LinuxProcess* this, Arg ioprio);
 void LinuxProcess_printDelay(float delay_percent, char* buffer, int n);
 #endif
 
-void LinuxProcess_writeField(Process* this, RichString* str, ProcessField field);
+void LinuxProcess_writeField(const Process* this, RichString* str, ProcessField field);
 
 long LinuxProcess_compare(const void* v1, const void* v2);
 
diff --git a/openbsd/OpenBSDProcess.c b/openbsd/OpenBSDProcess.c
index 56bc0771..bc6ef4a8 100644
--- a/openbsd/OpenBSDProcess.c
+++ b/openbsd/OpenBSDProcess.c
@@ -24,7 +24,7 @@ const ProcessClass OpenBSDProcess_class = {
       .delete = Process_delete,
       .compare = OpenBSDProcess_compare
    },
-   .writeField = (Process_WriteField) OpenBSDProcess_writeField,
+   .writeField = OpenBSDProcess_writeField,
 };
 
 ProcessFieldData Process_fields[] = {
@@ -178,7 +178,7 @@ void Process_delete(Object* cast) {
    free(this);
 }
 
-void OpenBSDProcess_writeField(Process* this, RichString* str, ProcessField field) {
+void OpenBSDProcess_writeField(const Process* this, RichString* str, ProcessField field) {
    //OpenBSDProcess* fp = (OpenBSDProcess*) this;
    char buffer[256]; buffer[255] = '\0';
    int attr = CRT_colors[DEFAULT_COLOR];
diff --git a/openbsd/OpenBSDProcess.h b/openbsd/OpenBSDProcess.h
index 5694a524..c9d4e381 100644
--- a/openbsd/OpenBSDProcess.h
+++ b/openbsd/OpenBSDProcess.h
@@ -31,7 +31,7 @@ OpenBSDProcess* OpenBSDProcess_new(Settings* settings);
 
 void Process_delete(Object* cast);
 
-void OpenBSDProcess_writeField(Process* this, RichString* str, ProcessField field);
+void OpenBSDProcess_writeField(const Process* this, RichString* str, ProcessField field);
 
 long OpenBSDProcess_compare(const void* v1, const void* v2);
 
diff --git a/solaris/SolarisProcess.c b/solaris/SolarisProcess.c
index 0d994669..13652bd3 100644
--- a/solaris/SolarisProcess.c
+++ b/solaris/SolarisProcess.c
@@ -25,7 +25,7 @@ const ProcessClass SolarisProcess_class = {
       .delete = Process_delete,
       .compare = SolarisProcess_compare
    },
-   .writeField = (Process_WriteField) SolarisProcess_writeField,
+   .writeField = SolarisProcess_writeField,
 };
 
 ProcessFieldData Process_fields[] = {
@@ -93,8 +93,8 @@ void Process_delete(Object* cast) {
    free(sp);
 }
 
-void SolarisProcess_writeField(Process* this, RichString* str, ProcessField field) {
-   SolarisProcess* sp = (SolarisProcess*) this;
+void SolarisProcess_writeField(const Process* this, RichString* str, ProcessField field) {
+   const SolarisProcess* sp = (const SolarisProcess*) this;
    char buffer[256]; buffer[255] = '\0';
    int attr = CRT_colors[DEFAULT_COLOR];
    int n = sizeof(buffer) - 1;
diff --git a/solaris/SolarisProcess.h b/solaris/SolarisProcess.h
index a1b3b14d..23012a2f 100644
--- a/solaris/SolarisProcess.h
+++ b/solaris/SolarisProcess.h
@@ -54,7 +54,7 @@ SolarisProcess* SolarisProcess_new(Settings* settings);
 
 void Process_delete(Object* cast);
 
-void SolarisProcess_writeField(Process* this, RichString* str, ProcessField field);
+void SolarisProcess_writeField(const Process* this, RichString* str, ProcessField field);
 
 long SolarisProcess_compare(const void* v1, const void* v2);